# HG changeset patch
# User Joerg Sonnenberger <joerg@bec.de>
# Date 1616975526 -7200
# Node ID d55b71393907e4c937bbad9da5527f35df9a41d7
# Parent  5fa019ceb49950dccd1bb28dc4a16f657a083e4c
node: replace nullid and friends with nodeconstants class

The introduction of 256bit hashes require changes to nullid and other
constant magic values. Start pushing them down from repository and
revlog where sensible.

Differential Revision: https://phab.mercurial-scm.org/D9465

diff -r 5fa019ceb499 -r d55b71393907 hgext/absorb.py
--- a/hgext/absorb.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/absorb.py	Mon Mar 29 01:52:06 2021 +0200
@@ -38,7 +38,6 @@
 from mercurial.i18n import _
 from mercurial.node import (
     hex,
-    nullid,
     short,
 )
 from mercurial import (
@@ -109,7 +108,7 @@
         return b''
 
     def node(self):
-        return nullid
+        return self._repo.nullid
 
 
 def uniq(lst):
@@ -927,7 +926,7 @@
         the commit is a clone from ctx, with a (optionally) different p1, and
         different file contents replaced by memworkingcopy.
         """
-        parents = p1 and (p1, nullid)
+        parents = p1 and (p1, self.repo.nullid)
         extra = ctx.extra()
         if self._useobsolete and self.ui.configbool(b'absorb', b'add-noise'):
             extra[b'absorb_source'] = ctx.hex()
diff -r 5fa019ceb499 -r d55b71393907 hgext/convert/git.py
--- a/hgext/convert/git.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/convert/git.py	Mon Mar 29 01:52:06 2021 +0200
@@ -9,7 +9,7 @@
 import os
 
 from mercurial.i18n import _
-from mercurial.node import nullhex
+from mercurial.node import sha1nodeconstants
 from mercurial import (
     config,
     error,
@@ -192,7 +192,7 @@
         return heads
 
     def catfile(self, rev, ftype):
-        if rev == nullhex:
+        if rev == sha1nodeconstants.nullhex:
             raise IOError
         self.catfilepipe[0].write(rev + b'\n')
         self.catfilepipe[0].flush()
@@ -214,7 +214,7 @@
         return data
 
     def getfile(self, name, rev):
-        if rev == nullhex:
+        if rev == sha1nodeconstants.nullhex:
             return None, None
         if name == b'.hgsub':
             data = b'\n'.join([m.hgsub() for m in self.submoditer()])
@@ -228,7 +228,7 @@
         return data, mode
 
     def submoditer(self):
-        null = nullhex
+        null = sha1nodeconstants.nullhex
         for m in sorted(self.submodules, key=lambda p: p.path):
             if m.node != null:
                 yield m
@@ -317,7 +317,7 @@
                 subexists[0] = True
                 if entry[4] == b'D' or renamesource:
                     subdeleted[0] = True
-                    changes.append((b'.hgsub', nullhex))
+                    changes.append((b'.hgsub', sha1nodeconstants.nullhex))
                 else:
                     changes.append((b'.hgsub', b''))
             elif entry[1] == b'160000' or entry[0] == b':160000':
@@ -325,7 +325,7 @@
                     subexists[0] = True
             else:
                 if renamesource:
-                    h = nullhex
+                    h = sha1nodeconstants.nullhex
                 self.modecache[(f, h)] = (p and b"x") or (s and b"l") or b""
                 changes.append((f, h))
 
@@ -362,7 +362,7 @@
 
         if subexists[0]:
             if subdeleted[0]:
-                changes.append((b'.hgsubstate', nullhex))
+                changes.append((b'.hgsubstate', sha1nodeconstants.nullhex))
             else:
                 self.retrievegitmodules(version)
                 changes.append((b'.hgsubstate', b''))
diff -r 5fa019ceb499 -r d55b71393907 hgext/convert/hg.py
--- a/hgext/convert/hg.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/convert/hg.py	Mon Mar 29 01:52:06 2021 +0200
@@ -27,8 +27,7 @@
 from mercurial.node import (
     bin,
     hex,
-    nullhex,
-    nullid,
+    sha1nodeconstants,
 )
 from mercurial import (
     bookmarks,
@@ -160,7 +159,7 @@
                 continue
             revid = revmap.get(source.lookuprev(s[0]))
             if not revid:
-                if s[0] == nullhex:
+                if s[0] == sha1nodeconstants.nullhex:
                     revid = s[0]
                 else:
                     # missing, but keep for hash stability
@@ -179,7 +178,7 @@
 
             revid = s[0]
             subpath = s[1]
-            if revid != nullhex:
+            if revid != sha1nodeconstants.nullhex:
                 revmap = self.subrevmaps.get(subpath)
                 if revmap is None:
                     revmap = mapfile(
@@ -304,9 +303,9 @@
             parent = parents[0]
 
         if len(parents) < 2:
-            parents.append(nullid)
+            parents.append(self.repo.nullid)
         if len(parents) < 2:
-            parents.append(nullid)
+            parents.append(self.repo.nullid)
         p2 = parents.pop(0)
 
         text = commit.desc
@@ -356,7 +355,7 @@
             p2 = parents.pop(0)
             p1ctx = self.repo[p1]
             p2ctx = None
-            if p2 != nullid:
+            if p2 != self.repo.nullid:
                 p2ctx = self.repo[p2]
             fileset = set(files)
             if full:
@@ -421,7 +420,7 @@
 
     def puttags(self, tags):
         tagparent = self.repo.branchtip(self.tagsbranch, ignoremissing=True)
-        tagparent = tagparent or nullid
+        tagparent = tagparent or self.repo.nullid
 
         oldlines = set()
         for branch, heads in pycompat.iteritems(self.repo.branchmap()):
diff -r 5fa019ceb499 -r d55b71393907 hgext/git/dirstate.py
--- a/hgext/git/dirstate.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/git/dirstate.py	Mon Mar 29 01:52:06 2021 +0200
@@ -4,7 +4,7 @@
 import errno
 import os
 
-from mercurial.node import nullid
+from mercurial.node import sha1nodeconstants
 from mercurial import (
     error,
     extensions,
@@ -81,14 +81,16 @@
         except pygit2.GitError:
             # Typically happens when peeling HEAD fails, as in an
             # empty repository.
-            return nullid
+            return sha1nodeconstants.nullid
 
     def p2(self):
         # TODO: MERGE_HEAD? something like that, right?
-        return nullid
+        return sha1nodeconstants.nullid
 
-    def setparents(self, p1, p2=nullid):
-        assert p2 == nullid, b'TODO merging support'
+    def setparents(self, p1, p2=None):
+        if p2 is None:
+            p2 = sha1nodeconstants.nullid
+        assert p2 == sha1nodeconstants.nullid, b'TODO merging support'
         self.git.head.set_target(gitutil.togitnode(p1))
 
     @util.propertycache
@@ -102,7 +104,7 @@
 
     def parents(self):
         # TODO how on earth do we find p2 if a merge is in flight?
-        return self.p1(), nullid
+        return self.p1(), sha1nodeconstants.nullid
 
     def __iter__(self):
         return (pycompat.fsencode(f.path) for f in self.git.index)
diff -r 5fa019ceb499 -r d55b71393907 hgext/git/gitlog.py
--- a/hgext/git/gitlog.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/git/gitlog.py	Mon Mar 29 01:52:06 2021 +0200
@@ -5,11 +5,8 @@
 from mercurial.node import (
     bin,
     hex,
-    nullhex,
-    nullid,
     nullrev,
     sha1nodeconstants,
-    wdirhex,
 )
 from mercurial import (
     ancestor,
@@ -47,7 +44,7 @@
         )
 
     def rev(self, n):
-        if n == nullid:
+        if n == sha1nodeconstants.nullid:
             return -1
         t = self._db.execute(
             'SELECT rev FROM changelog WHERE node = ?', (gitutil.togitnode(n),)
@@ -58,7 +55,7 @@
 
     def node(self, r):
         if r == nullrev:
-            return nullid
+            return sha1nodeconstants.nullid
         t = self._db.execute(
             'SELECT node FROM changelog WHERE rev = ?', (r,)
         ).fetchone()
@@ -134,7 +131,7 @@
             bin(v[0]): v[1]
             for v in self._db.execute('SELECT node, rev FROM changelog')
         }
-        r[nullid] = nullrev
+        r[sha1nodeconstants.nullid] = nullrev
         return r
 
     def tip(self):
@@ -143,7 +140,7 @@
         ).fetchone()
         if t:
             return bin(t[0])
-        return nullid
+        return sha1nodeconstants.nullid
 
     def revs(self, start=0, stop=None):
         if stop is None:
@@ -163,7 +160,7 @@
         return next(t)
 
     def _partialmatch(self, id):
-        if wdirhex.startswith(id):
+        if sha1nodeconstants.wdirhex.startswith(id):
             raise error.WdirUnsupported
         candidates = [
             bin(x[0])
@@ -171,8 +168,8 @@
                 'SELECT node FROM changelog WHERE node LIKE ?', (id + b'%',)
             )
         ]
-        if nullhex.startswith(id):
-            candidates.append(nullid)
+        if sha1nodeconstants.nullhex.startswith(id):
+            candidates.append(sha1nodeconstants.nullid)
         if len(candidates) > 1:
             raise error.AmbiguousPrefixLookupError(
                 id, b'00changelog.i', _(b'ambiguous identifier')
@@ -217,8 +214,10 @@
         else:
             n = nodeorrev
         # handle looking up nullid
-        if n == nullid:
-            return hgchangelog._changelogrevision(extra={}, manifest=nullid)
+        if n == sha1nodeconstants.nullid:
+            return hgchangelog._changelogrevision(
+                extra={}, manifest=sha1nodeconstants.nullid
+            )
         hn = gitutil.togitnode(n)
         # We've got a real commit!
         files = [
@@ -234,7 +233,7 @@
             for r in self._db.execute(
                 'SELECT filename FROM changedfiles '
                 'WHERE node = ? and filenode = ?',
-                (hn, nullhex),
+                (hn, sha1nodeconstants.nullhex),
             )
         ]
         c = self.gitrepo[hn]
@@ -295,7 +294,7 @@
         not supplied, uses all of the revlog's heads.  If common is not
         supplied, uses nullid."""
         if common is None:
-            common = [nullid]
+            common = [sha1nodeconstants.nullid]
         if heads is None:
             heads = self.heads()
 
@@ -394,9 +393,9 @@
     ):
         parents = []
         hp1, hp2 = gitutil.togitnode(p1), gitutil.togitnode(p2)
-        if p1 != nullid:
+        if p1 != sha1nodeconstants.nullid:
             parents.append(hp1)
-        if p2 and p2 != nullid:
+        if p2 and p2 != sha1nodeconstants.nullid:
             parents.append(hp2)
         assert date is not None
         timestamp, tz = date
@@ -429,7 +428,7 @@
         return self.get(b'', node)
 
     def get(self, relpath, node):
-        if node == nullid:
+        if node == sha1nodeconstants.nullid:
             # TODO: this should almost certainly be a memgittreemanifestctx
             return manifest.memtreemanifestctx(self, relpath)
         commit = self.gitrepo[gitutil.togitnode(node)]
@@ -448,9 +447,10 @@
         super(filelog, self).__init__(gr, db)
         assert isinstance(path, bytes)
         self.path = path
+        self.nullid = sha1nodeconstants.nullid
 
     def read(self, node):
-        if node == nullid:
+        if node == sha1nodeconstants.nullid:
             return b''
         return self.gitrepo[gitutil.togitnode(node)].data
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/git/gitutil.py
--- a/hgext/git/gitutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/git/gitutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -1,7 +1,7 @@
 """utilities to assist in working with pygit2"""
 from __future__ import absolute_import
 
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex, sha1nodeconstants
 
 from mercurial import pycompat
 
@@ -50,4 +50,4 @@
     return bin(n)
 
 
-nullgit = togitnode(nullid)
+nullgit = togitnode(sha1nodeconstants.nullid)
diff -r 5fa019ceb499 -r d55b71393907 hgext/git/index.py
--- a/hgext/git/index.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/git/index.py	Mon Mar 29 01:52:06 2021 +0200
@@ -5,10 +5,7 @@
 import sqlite3
 
 from mercurial.i18n import _
-from mercurial.node import (
-    nullhex,
-    nullid,
-)
+from mercurial.node import sha1nodeconstants
 
 from mercurial import (
     encoding,
@@ -281,7 +278,7 @@
     for pos, commit in enumerate(walker):
         if prog is not None:
             prog.update(pos)
-        p1 = p2 = nullhex
+        p1 = p2 = sha1nodeconstants.nullhex
         if len(commit.parents) > 2:
             raise error.ProgrammingError(
                 (
@@ -318,7 +315,9 @@
                 )
             new_files = (p.delta.new_file for p in patchgen)
             files = {
-                nf.path: nf.id.hex for nf in new_files if nf.id.raw != nullid
+                nf.path: nf.id.hex
+                for nf in new_files
+                if nf.id.raw != sha1nodeconstants.nullid
             }
             for p, n in files.items():
                 # We intentionally set NULLs for any file parentage
diff -r 5fa019ceb499 -r d55b71393907 hgext/gpg.py
--- a/hgext/gpg.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/gpg.py	Mon Mar 29 01:52:06 2021 +0200
@@ -14,7 +14,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     short,
 )
 from mercurial import (
@@ -314,7 +313,9 @@
     if revs:
         nodes = [repo.lookup(n) for n in revs]
     else:
-        nodes = [node for node in repo.dirstate.parents() if node != nullid]
+        nodes = [
+            node for node in repo.dirstate.parents() if node != repo.nullid
+        ]
         if len(nodes) > 1:
             raise error.Abort(
                 _(b'uncommitted merge - please provide a specific revision')
diff -r 5fa019ceb499 -r d55b71393907 hgext/hgk.py
--- a/hgext/hgk.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/hgk.py	Mon Mar 29 01:52:06 2021 +0200
@@ -40,7 +40,6 @@
 
 from mercurial.i18n import _
 from mercurial.node import (
-    nullid,
     nullrev,
     short,
 )
@@ -95,7 +94,7 @@
         mmap2 = repo[node2].manifest()
         m = scmutil.match(repo[node1], files)
         st = repo.status(node1, node2, m)
-        empty = short(nullid)
+        empty = short(repo.nullid)
 
         for f in st.modified:
             # TODO get file permissions
@@ -317,9 +316,9 @@
             parentstr = b""
             if parents:
                 pp = repo.changelog.parents(n)
-                if pp[0] != nullid:
+                if pp[0] != repo.nullid:
                     parentstr += b" " + short(pp[0])
-                if pp[1] != nullid:
+                if pp[1] != repo.nullid:
                     parentstr += b" " + short(pp[1])
             if not full:
                 ui.write(b"%s%s\n" % (short(n), parentstr))
diff -r 5fa019ceb499 -r d55b71393907 hgext/journal.py
--- a/hgext/journal.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/journal.py	Mon Mar 29 01:52:06 2021 +0200
@@ -22,7 +22,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
 )
 
 from mercurial import (
@@ -117,8 +116,8 @@
     new = list(new)
     if util.safehasattr(dirstate, 'journalstorage'):
         # only record two hashes if there was a merge
-        oldhashes = old[:1] if old[1] == nullid else old
-        newhashes = new[:1] if new[1] == nullid else new
+        oldhashes = old[:1] if old[1] == dirstate._nodeconstants.nullid else old
+        newhashes = new[:1] if new[1] == dirstate._nodeconstants.nullid else new
         dirstate.journalstorage.record(
             wdirparenttype, b'.', oldhashes, newhashes
         )
@@ -131,7 +130,7 @@
     if util.safehasattr(repo, 'journal'):
         oldmarks = bookmarks.bmstore(repo)
         for mark, value in pycompat.iteritems(store):
-            oldvalue = oldmarks.get(mark, nullid)
+            oldvalue = oldmarks.get(mark, repo.nullid)
             if value != oldvalue:
                 repo.journal.record(bookmarktype, mark, oldvalue, value)
     return orig(store, fp)
diff -r 5fa019ceb499 -r d55b71393907 hgext/largefiles/basestore.py
--- a/hgext/largefiles/basestore.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/largefiles/basestore.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,7 +11,8 @@
 
 from mercurial.i18n import _
 
-from mercurial import node, util
+from mercurial.node import short
+from mercurial import util
 from mercurial.utils import (
     urlutil,
 )
@@ -137,7 +138,7 @@
         filestocheck = []  # list of (cset, filename, expectedhash)
         for rev in revs:
             cctx = self.repo[rev]
-            cset = b"%d:%s" % (cctx.rev(), node.short(cctx.node()))
+            cset = b"%d:%s" % (cctx.rev(), short(cctx.node()))
 
             for standin in cctx:
                 filename = lfutil.splitstandin(standin)
diff -r 5fa019ceb499 -r d55b71393907 hgext/largefiles/lfcommands.py
--- a/hgext/largefiles/lfcommands.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/largefiles/lfcommands.py	Mon Mar 29 01:52:06 2021 +0200
@@ -17,7 +17,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
 )
 
 from mercurial import (
@@ -115,7 +114,7 @@
             rsrc[ctx]
             for ctx in rsrc.changelog.nodesbetween(None, rsrc.heads())[0]
         )
-        revmap = {nullid: nullid}
+        revmap = {rsrc.nullid: rdst.nullid}
         if tolfile:
             # Lock destination to prevent modification while it is converted to.
             # Don't need to lock src because we are just reading from its
@@ -340,7 +339,7 @@
 # Generate list of changed files
 def _getchangedfiles(ctx, parents):
     files = set(ctx.files())
-    if nullid not in parents:
+    if ctx.repo().nullid not in parents:
         mc = ctx.manifest()
         for pctx in ctx.parents():
             for fn in pctx.manifest().diff(mc):
@@ -354,7 +353,7 @@
     for p in ctx.parents():
         parents.append(revmap[p.node()])
     while len(parents) < 2:
-        parents.append(nullid)
+        parents.append(ctx.repo().nullid)
     return parents
 
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/largefiles/lfutil.py
--- a/hgext/largefiles/lfutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/largefiles/lfutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -15,10 +15,7 @@
 import stat
 
 from mercurial.i18n import _
-from mercurial.node import (
-    hex,
-    nullid,
-)
+from mercurial.node import hex
 from mercurial.pycompat import open
 
 from mercurial import (
@@ -613,7 +610,7 @@
     ) as progress:
         for i, n in enumerate(missing):
             progress.update(i)
-            parents = [p for p in repo[n].parents() if p != nullid]
+            parents = [p for p in repo[n].parents() if p != repo.nullid]
 
             with lfstatus(repo, value=False):
                 ctx = repo[n]
diff -r 5fa019ceb499 -r d55b71393907 hgext/lfs/wrapper.py
--- a/hgext/lfs/wrapper.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/lfs/wrapper.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,7 +10,7 @@
 import hashlib
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid, short
+from mercurial.node import bin, hex, short
 from mercurial.pycompat import (
     getattr,
     setattr,
@@ -158,7 +158,7 @@
         rev = rlog.rev(node)
     else:
         node = rlog.node(rev)
-    if node == nullid:
+    if node == rlog.nullid:
         return False
     flags = rlog.flags(rev)
     return bool(flags & revlog.REVIDX_EXTSTORED)
diff -r 5fa019ceb499 -r d55b71393907 hgext/mq.py
--- a/hgext/mq.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/mq.py	Mon Mar 29 01:52:06 2021 +0200
@@ -73,7 +73,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -908,13 +907,13 @@
         """
         if rev is None:
             (p1, p2) = repo.dirstate.parents()
-            if p2 == nullid:
+            if p2 == repo.nullid:
                 return p1
             if not self.applied:
                 return None
             return self.applied[-1].node
         p1, p2 = repo.changelog.parents(rev)
-        if p2 != nullid and p2 in [x.node for x in self.applied]:
+        if p2 != repo.nullid and p2 in [x.node for x in self.applied]:
             return p2
         return p1
 
@@ -1591,7 +1590,7 @@
             for hs in repo.branchmap().iterheads():
                 heads.extend(hs)
             if not heads:
-                heads = [nullid]
+                heads = [repo.nullid]
             if repo.dirstate.p1() not in heads and not exact:
                 self.ui.status(_(b"(working directory not at a head)\n"))
 
@@ -1857,7 +1856,7 @@
                         fctx = ctx[f]
                         repo.wwrite(f, fctx.data(), fctx.flags())
                         repo.dirstate.normal(f)
-                    repo.setparents(qp, nullid)
+                    repo.setparents(qp, repo.nullid)
             for patch in reversed(self.applied[start:end]):
                 self.ui.status(_(b"popping %s\n") % patch.name)
             del self.applied[start:end]
diff -r 5fa019ceb499 -r d55b71393907 hgext/narrow/narrowbundle2.py
--- a/hgext/narrow/narrowbundle2.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/narrow/narrowbundle2.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,7 +11,6 @@
 import struct
 
 from mercurial.i18n import _
-from mercurial.node import nullid
 from mercurial import (
     bundle2,
     changegroup,
@@ -94,7 +93,7 @@
             raise error.Abort(_(b'depth must be positive, got %d') % depth)
 
     heads = set(heads or repo.heads())
-    common = set(common or [nullid])
+    common = set(common or [repo.nullid])
 
     visitnodes, relevant_nodes, ellipsisroots = exchange._computeellipsis(
         repo, common, heads, set(), match, depth=depth
@@ -128,7 +127,7 @@
     common,
     known,
 ):
-    common = set(common or [nullid])
+    common = set(common or [repo.nullid])
     # Steps:
     # 1. Send kill for "$known & ::common"
     #
diff -r 5fa019ceb499 -r d55b71393907 hgext/narrow/narrowcommands.py
--- a/hgext/narrow/narrowcommands.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/narrow/narrowcommands.py	Mon Mar 29 01:52:06 2021 +0200
@@ -12,7 +12,6 @@
 from mercurial.i18n import _
 from mercurial.node import (
     hex,
-    nullid,
     short,
 )
 from mercurial import (
@@ -193,7 +192,7 @@
         kwargs[b'known'] = [
             hex(ctx.node())
             for ctx in repo.set(b'::%ln', pullop.common)
-            if ctx.node() != nullid
+            if ctx.node() != repo.nullid
         ]
         if not kwargs[b'known']:
             # Mercurial serializes an empty list as '' and deserializes it as
@@ -370,7 +369,7 @@
             ds = repo.dirstate
             p1, p2 = ds.p1(), ds.p2()
             with ds.parentchange():
-                ds.setparents(nullid, nullid)
+                ds.setparents(repo.nullid, repo.nullid)
         if isoldellipses:
             with wrappedextraprepare:
                 exchange.pull(repo, remote, heads=common)
@@ -380,7 +379,7 @@
                 known = [
                     ctx.node()
                     for ctx in repo.set(b'::%ln', common)
-                    if ctx.node() != nullid
+                    if ctx.node() != repo.nullid
                 ]
             with remote.commandexecutor() as e:
                 bundle = e.callcommand(
diff -r 5fa019ceb499 -r d55b71393907 hgext/phabricator.py
--- a/hgext/phabricator.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/phabricator.py	Mon Mar 29 01:52:06 2021 +0200
@@ -69,7 +69,7 @@
 import re
 import time
 
-from mercurial.node import bin, nullid, short
+from mercurial.node import bin, short
 from mercurial.i18n import _
 from mercurial.pycompat import getattr
 from mercurial.thirdparty import attr
@@ -586,7 +586,7 @@
                 tags.tag(
                     repo,
                     tagname,
-                    nullid,
+                    repo.nullid,
                     message=None,
                     user=None,
                     date=None,
@@ -1606,7 +1606,7 @@
                         tags.tag(
                             repo,
                             tagname,
-                            nullid,
+                            repo.nullid,
                             message=None,
                             user=None,
                             date=None,
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/contentstore.py
--- a/hgext/remotefilelog/contentstore.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/contentstore.py	Mon Mar 29 01:52:06 2021 +0200
@@ -2,7 +2,10 @@
 
 import threading
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from mercurial.pycompat import getattr
 from mercurial import (
     mdiff,
@@ -55,7 +58,7 @@
         """
         chain = self.getdeltachain(name, node)
 
-        if chain[-1][ChainIndicies.BASENODE] != nullid:
+        if chain[-1][ChainIndicies.BASENODE] != sha1nodeconstants.nullid:
             # If we didn't receive a full chain, throw
             raise KeyError((name, hex(node)))
 
@@ -92,7 +95,7 @@
         deltabasenode.
         """
         chain = self._getpartialchain(name, node)
-        while chain[-1][ChainIndicies.BASENODE] != nullid:
+        while chain[-1][ChainIndicies.BASENODE] != sha1nodeconstants.nullid:
             x, x, deltabasename, deltabasenode, x = chain[-1]
             try:
                 morechain = self._getpartialchain(deltabasename, deltabasenode)
@@ -187,7 +190,12 @@
         # Since remotefilelog content stores only contain full texts, just
         # return that.
         revision = self.get(name, node)
-        return revision, name, nullid, self.getmeta(name, node)
+        return (
+            revision,
+            name,
+            sha1nodeconstants.nullid,
+            self.getmeta(name, node),
+        )
 
     def getdeltachain(self, name, node):
         # Since remotefilelog content stores just contain full texts, we return
@@ -195,7 +203,7 @@
         # The nullid in the deltabasenode slot indicates that the revision is a
         # fulltext.
         revision = self.get(name, node)
-        return [(name, node, None, nullid, revision)]
+        return [(name, node, None, sha1nodeconstants.nullid, revision)]
 
     def getmeta(self, name, node):
         self._sanitizemetacache()
@@ -237,7 +245,12 @@
 
     def getdelta(self, name, node):
         revision = self.get(name, node)
-        return revision, name, nullid, self._shared.getmeta(name, node)
+        return (
+            revision,
+            name,
+            sha1nodeconstants.nullid,
+            self._shared.getmeta(name, node),
+        )
 
     def getdeltachain(self, name, node):
         # Since our remote content stores just contain full texts, we return a
@@ -245,7 +258,7 @@
         # The nullid in the deltabasenode slot indicates that the revision is a
         # fulltext.
         revision = self.get(name, node)
-        return [(name, node, None, nullid, revision)]
+        return [(name, node, None, sha1nodeconstants.nullid, revision)]
 
     def getmeta(self, name, node):
         self._fileservice.prefetch(
@@ -276,11 +289,11 @@
 
     def getdelta(self, name, node):
         revision = self.get(name, node)
-        return revision, name, nullid, self.getmeta(name, node)
+        return revision, name, self._cl.nullid, self.getmeta(name, node)
 
     def getdeltachain(self, name, node):
         revision = self.get(name, node)
-        return [(name, node, None, nullid, revision)]
+        return [(name, node, None, self._cl.nullid, revision)]
 
     def getmeta(self, name, node):
         rl = self._revlog(name)
@@ -304,9 +317,9 @@
             missing.discard(ancnode)
 
             p1, p2 = rl.parents(ancnode)
-            if p1 != nullid and p1 not in known:
+            if p1 != self._cl.nullid and p1 not in known:
                 missing.add(p1)
-            if p2 != nullid and p2 not in known:
+            if p2 != self._cl.nullid and p2 not in known:
                 missing.add(p2)
 
             linknode = self._cl.node(rl.linkrev(ancrev))
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/datapack.py
--- a/hgext/remotefilelog/datapack.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/datapack.py	Mon Mar 29 01:52:06 2021 +0200
@@ -3,7 +3,10 @@
 import struct
 import zlib
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from mercurial.i18n import _
 from mercurial import (
     pycompat,
@@ -458,7 +461,7 @@
         rawindex = b''
         fmt = self.INDEXFORMAT
         for node, deltabase, offset, size in entries:
-            if deltabase == nullid:
+            if deltabase == sha1nodeconstants.nullid:
                 deltabaselocation = FULLTEXTINDEXMARK
             else:
                 # Instead of storing the deltabase node in the index, let's
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/debugcommands.py
--- a/hgext/remotefilelog/debugcommands.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/debugcommands.py	Mon Mar 29 01:52:06 2021 +0200
@@ -12,7 +12,7 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
+    sha1nodeconstants,
     short,
 )
 from mercurial.i18n import _
@@ -57,9 +57,9 @@
             _(b"%s => %s  %s  %s  %s\n")
             % (short(node), short(p1), short(p2), short(linknode), copyfrom)
         )
-        if p1 != nullid:
+        if p1 != sha1nodeconstants.nullid:
             queue.append(p1)
-        if p2 != nullid:
+        if p2 != sha1nodeconstants.nullid:
             queue.append(p2)
 
 
@@ -152,7 +152,7 @@
             try:
                 pp = r.parents(node)
             except Exception:
-                pp = [nullid, nullid]
+                pp = [repo.nullid, repo.nullid]
             ui.write(
                 b"% 6d % 9d % 7d % 6d % 7d %s %s %s\n"
                 % (
@@ -197,7 +197,7 @@
         node = r.node(i)
         pp = r.parents(node)
         ui.write(b"\t%d -> %d\n" % (r.rev(pp[0]), i))
-        if pp[1] != nullid:
+        if pp[1] != repo.nullid:
             ui.write(b"\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write(b"}\n")
 
@@ -212,7 +212,7 @@
             filepath = os.path.join(root, file)
             size, firstnode, mapping = parsefileblob(filepath, decompress)
             for p1, p2, linknode, copyfrom in pycompat.itervalues(mapping):
-                if linknode == nullid:
+                if linknode == sha1nodeconstants.nullid:
                     actualpath = os.path.relpath(root, path)
                     key = fileserverclient.getcachekey(
                         b"reponame", actualpath, file
@@ -371,7 +371,7 @@
         current = node
         deltabase = bases[current]
 
-        while deltabase != nullid:
+        while deltabase != sha1nodeconstants.nullid:
             if deltabase not in nodes:
                 ui.warn(
                     (
@@ -397,7 +397,7 @@
             deltabase = bases[current]
         # Since ``node`` begins a valid chain, reset/memoize its base to nullid
         # so we don't traverse it again.
-        bases[node] = nullid
+        bases[node] = sha1nodeconstants.nullid
     return failures
 
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/fileserverclient.py
--- a/hgext/remotefilelog/fileserverclient.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/fileserverclient.py	Mon Mar 29 01:52:06 2021 +0200
@@ -14,7 +14,7 @@
 import zlib
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex
 from mercurial import (
     error,
     pycompat,
@@ -599,9 +599,13 @@
 
         # partition missing nodes into nullid and not-nullid so we can
         # warn about this filtering potentially shadowing bugs.
-        nullids = len([None for unused, id in missingids if id == nullid])
+        nullids = len(
+            [None for unused, id in missingids if id == self.repo.nullid]
+        )
         if nullids:
-            missingids = [(f, id) for f, id in missingids if id != nullid]
+            missingids = [
+                (f, id) for f, id in missingids if id != self.repo.nullid
+            ]
             repo.ui.develwarn(
                 (
                     b'remotefilelog not fetching %d null revs'
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/historypack.py
--- a/hgext/remotefilelog/historypack.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/historypack.py	Mon Mar 29 01:52:06 2021 +0200
@@ -2,7 +2,10 @@
 
 import struct
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from mercurial import (
     pycompat,
     util,
@@ -147,9 +150,9 @@
                 pending.remove(ancnode)
                 p1node = entry[ANC_P1NODE]
                 p2node = entry[ANC_P2NODE]
-                if p1node != nullid and p1node not in known:
+                if p1node != sha1nodeconstants.nullid and p1node not in known:
                     pending.add(p1node)
-                if p2node != nullid and p2node not in known:
+                if p2node != sha1nodeconstants.nullid and p2node not in known:
                     pending.add(p2node)
 
                 yield (ancnode, p1node, p2node, entry[ANC_LINKNODE], copyfrom)
@@ -457,9 +460,9 @@
             def parentfunc(node):
                 x, p1, p2, x, x, x = entrymap[node]
                 parents = []
-                if p1 != nullid:
+                if p1 != sha1nodeconstants.nullid:
                     parents.append(p1)
-                if p2 != nullid:
+                if p2 != sha1nodeconstants.nullid:
                     parents.append(p2)
                 return parents
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/metadatastore.py
--- a/hgext/remotefilelog/metadatastore.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/metadatastore.py	Mon Mar 29 01:52:06 2021 +0200
@@ -1,6 +1,9 @@
 from __future__ import absolute_import
 
-from mercurial.node import hex, nullid
+from mercurial.node import (
+    hex,
+    sha1nodeconstants,
+)
 from . import (
     basestore,
     shallowutil,
@@ -51,9 +54,9 @@
                     missing.append((name, node))
                     continue
                 p1, p2, linknode, copyfrom = value
-                if p1 != nullid and p1 not in known:
+                if p1 != sha1nodeconstants.nullid and p1 not in known:
                     queue.append((copyfrom or curname, p1))
-                if p2 != nullid and p2 not in known:
+                if p2 != sha1nodeconstants.nullid and p2 not in known:
                     queue.append((curname, p2))
             return missing
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/remotefilectx.py
--- a/hgext/remotefilelog/remotefilectx.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/remotefilectx.py	Mon Mar 29 01:52:06 2021 +0200
@@ -9,7 +9,7 @@
 import collections
 import time
 
-from mercurial.node import bin, hex, nullid, nullrev
+from mercurial.node import bin, hex, nullrev
 from mercurial import (
     ancestor,
     context,
@@ -35,7 +35,7 @@
         ancestormap=None,
     ):
         if fileid == nullrev:
-            fileid = nullid
+            fileid = repo.nullid
         if fileid and len(fileid) == 40:
             fileid = bin(fileid)
         super(remotefilectx, self).__init__(
@@ -78,7 +78,7 @@
 
     @propertycache
     def _linkrev(self):
-        if self._filenode == nullid:
+        if self._filenode == self._repo.nullid:
             return nullrev
 
         ancestormap = self.ancestormap()
@@ -174,7 +174,7 @@
 
         p1, p2, linknode, copyfrom = ancestormap[self._filenode]
         results = []
-        if p1 != nullid:
+        if p1 != repo.nullid:
             path = copyfrom or self._path
             flog = repo.file(path)
             p1ctx = remotefilectx(
@@ -183,7 +183,7 @@
             p1ctx._descendantrev = self.rev()
             results.append(p1ctx)
 
-        if p2 != nullid:
+        if p2 != repo.nullid:
             path = self._path
             flog = repo.file(path)
             p2ctx = remotefilectx(
@@ -504,25 +504,25 @@
             if renamed:
                 p1 = renamed
             else:
-                p1 = (path, pcl[0]._manifest.get(path, nullid))
+                p1 = (path, pcl[0]._manifest.get(path, self._repo.nullid))
 
-            p2 = (path, nullid)
+            p2 = (path, self._repo.nullid)
             if len(pcl) > 1:
-                p2 = (path, pcl[1]._manifest.get(path, nullid))
+                p2 = (path, pcl[1]._manifest.get(path, self._repo.nullid))
 
             m = {}
-            if p1[1] != nullid:
+            if p1[1] != self._repo.nullid:
                 p1ctx = self._repo.filectx(p1[0], fileid=p1[1])
                 m.update(p1ctx.filelog().ancestormap(p1[1]))
 
-            if p2[1] != nullid:
+            if p2[1] != self._repo.nullid:
                 p2ctx = self._repo.filectx(p2[0], fileid=p2[1])
                 m.update(p2ctx.filelog().ancestormap(p2[1]))
 
             copyfrom = b''
             if renamed:
                 copyfrom = renamed[0]
-            m[None] = (p1[1], p2[1], nullid, copyfrom)
+            m[None] = (p1[1], p2[1], self._repo.nullid, copyfrom)
             self._ancestormap = m
 
         return self._ancestormap
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/remotefilelog.py
--- a/hgext/remotefilelog/remotefilelog.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/remotefilelog.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,12 +10,7 @@
 import collections
 import os
 
-from mercurial.node import (
-    bin,
-    nullid,
-    wdirfilenodeids,
-    wdirid,
-)
+from mercurial.node import bin
 from mercurial.i18n import _
 from mercurial import (
     ancestor,
@@ -100,7 +95,7 @@
 
         pancestors = {}
         queue = []
-        if realp1 != nullid:
+        if realp1 != self.repo.nullid:
             p1flog = self
             if copyfrom:
                 p1flog = remotefilelog(self.opener, copyfrom, self.repo)
@@ -108,7 +103,7 @@
             pancestors.update(p1flog.ancestormap(realp1))
             queue.append(realp1)
             visited.add(realp1)
-        if p2 != nullid:
+        if p2 != self.repo.nullid:
             pancestors.update(self.ancestormap(p2))
             queue.append(p2)
             visited.add(p2)
@@ -129,10 +124,10 @@
                 pacopyfrom,
             )
 
-            if pa1 != nullid and pa1 not in visited:
+            if pa1 != self.repo.nullid and pa1 not in visited:
                 queue.append(pa1)
                 visited.add(pa1)
-            if pa2 != nullid and pa2 not in visited:
+            if pa2 != self.repo.nullid and pa2 not in visited:
                 queue.append(pa2)
                 visited.add(pa2)
 
@@ -238,7 +233,7 @@
         returns True if text is different than what is stored.
         """
 
-        if node == nullid:
+        if node == self.repo.nullid:
             return True
 
         nodetext = self.read(node)
@@ -275,13 +270,13 @@
         return store.getmeta(self.filename, node).get(constants.METAKEYFLAG, 0)
 
     def parents(self, node):
-        if node == nullid:
-            return nullid, nullid
+        if node == self.repo.nullid:
+            return self.repo.nullid, self.repo.nullid
 
         ancestormap = self.repo.metadatastore.getancestors(self.filename, node)
         p1, p2, linknode, copyfrom = ancestormap[node]
         if copyfrom:
-            p1 = nullid
+            p1 = self.repo.nullid
 
         return p1, p2
 
@@ -317,8 +312,8 @@
             if prevnode is None:
                 basenode = prevnode = p1
             if basenode == node:
-                basenode = nullid
-            if basenode != nullid:
+                basenode = self.repo.nullid
+            if basenode != self.repo.nullid:
                 revision = None
                 delta = self.revdiff(basenode, node)
             else:
@@ -380,13 +375,16 @@
         this is generally only used for bundling and communicating with vanilla
         hg clients.
         """
-        if node == nullid:
+        if node == self.repo.nullid:
             return b""
         if len(node) != 20:
             raise error.LookupError(
                 node, self.filename, _(b'invalid revision input')
             )
-        if node == wdirid or node in wdirfilenodeids:
+        if (
+            node == self.repo.nodeconstants.wdirid
+            or node in self.repo.nodeconstants.wdirfilenodeids
+        ):
             raise error.WdirUnsupported
 
         store = self.repo.contentstore
@@ -432,8 +430,8 @@
         return self.repo.metadatastore.getancestors(self.filename, node)
 
     def ancestor(self, a, b):
-        if a == nullid or b == nullid:
-            return nullid
+        if a == self.repo.nullid or b == self.repo.nullid:
+            return self.repo.nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
         nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
@@ -442,13 +440,13 @@
         if ancs:
             # choose a consistent winner when there's a tie
             return min(map(nodemap.__getitem__, ancs))
-        return nullid
+        return self.repo.nullid
 
     def commonancestorsheads(self, a, b):
         """calculate all the heads of the common ancestors of nodes a and b"""
 
-        if a == nullid or b == nullid:
-            return nullid
+        if a == self.repo.nullid or b == self.repo.nullid:
+            return self.repo.nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
         nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
@@ -472,10 +470,10 @@
                 p1, p2, linknode, copyfrom = pdata
                 # Don't follow renames (copyfrom).
                 # remotefilectx.ancestor does that.
-                if p1 != nullid and not copyfrom:
+                if p1 != self.repo.nullid and not copyfrom:
                     parents.append(p1)
                     allparents.add(p1)
-                if p2 != nullid:
+                if p2 != self.repo.nullid:
                     parents.append(p2)
                     allparents.add(p2)
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/remotefilelogserver.py
--- a/hgext/remotefilelog/remotefilelogserver.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/remotefilelogserver.py	Mon Mar 29 01:52:06 2021 +0200
@@ -13,7 +13,7 @@
 import zlib
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex
 from mercurial.pycompat import open
 from mercurial import (
     changegroup,
@@ -242,7 +242,7 @@
     filecachepath = os.path.join(cachepath, path, hex(node))
     if not os.path.exists(filecachepath) or os.path.getsize(filecachepath) == 0:
         filectx = repo.filectx(path, fileid=node)
-        if filectx.node() == nullid:
+        if filectx.node() == repo.nullid:
             repo.changelog = changelog.changelog(repo.svfs)
             filectx = repo.filectx(path, fileid=node)
 
@@ -284,7 +284,7 @@
     """A server api for requesting a filelog's heads"""
     flog = repo.file(path)
     heads = flog.heads()
-    return b'\n'.join((hex(head) for head in heads if head != nullid))
+    return b'\n'.join((hex(head) for head in heads if head != repo.nullid))
 
 
 def getfile(repo, proto, file, node):
@@ -302,7 +302,7 @@
     if not cachepath:
         cachepath = os.path.join(repo.path, b"remotefilelogcache")
     node = bin(node.strip())
-    if node == nullid:
+    if node == repo.nullid:
         return b'0\0'
     return b'0\0' + _loadfileblob(repo, cachepath, file, node)
 
@@ -327,7 +327,7 @@
                 break
 
             node = bin(request[:40])
-            if node == nullid:
+            if node == repo.nullid:
                 yield b'0\n'
                 continue
 
@@ -380,8 +380,8 @@
         ancestortext = b""
         for ancestorctx in ancestors:
             parents = ancestorctx.parents()
-            p1 = nullid
-            p2 = nullid
+            p1 = repo.nullid
+            p2 = repo.nullid
             if len(parents) > 0:
                 p1 = parents[0].filenode()
             if len(parents) > 1:
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/repack.py
--- a/hgext/remotefilelog/repack.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/repack.py	Mon Mar 29 01:52:06 2021 +0200
@@ -4,10 +4,7 @@
 import time
 
 from mercurial.i18n import _
-from mercurial.node import (
-    nullid,
-    short,
-)
+from mercurial.node import short
 from mercurial import (
     encoding,
     error,
@@ -586,7 +583,7 @@
         # Create one contiguous chain and reassign deltabases.
         for i, node in enumerate(orphans):
             if i == 0:
-                deltabases[node] = (nullid, 0)
+                deltabases[node] = (self.repo.nullid, 0)
             else:
                 parent = orphans[i - 1]
                 deltabases[node] = (parent, deltabases[parent][1] + 1)
@@ -676,8 +673,8 @@
                 # of immediate child
                 deltatuple = deltabases.get(node, None)
                 if deltatuple is None:
-                    deltabase, chainlen = nullid, 0
-                    deltabases[node] = (nullid, 0)
+                    deltabase, chainlen = self.repo.nullid, 0
+                    deltabases[node] = (self.repo.nullid, 0)
                     nobase.add(node)
                 else:
                     deltabase, chainlen = deltatuple
@@ -692,7 +689,7 @@
                     # file was copied from elsewhere. So don't attempt to do any
                     # deltas with the other file.
                     if copyfrom:
-                        p1 = nullid
+                        p1 = self.repo.nullid
 
                     if chainlen < maxchainlen:
                         # Record this child as the delta base for its parents.
@@ -700,9 +697,9 @@
                         # many children, and this will only choose the last one.
                         # TODO: record all children and try all deltas to find
                         # best
-                        if p1 != nullid:
+                        if p1 != self.repo.nullid:
                             deltabases[p1] = (node, chainlen + 1)
-                        if p2 != nullid:
+                        if p2 != self.repo.nullid:
                             deltabases[p2] = (node, chainlen + 1)
 
             # experimental config: repack.chainorphansbysize
@@ -719,7 +716,7 @@
                 # TODO: Optimize the deltachain fetching. Since we're
                 # iterating over the different version of the file, we may
                 # be fetching the same deltachain over and over again.
-                if deltabase != nullid:
+                if deltabase != self.repo.nullid:
                     deltaentry = self.data.getdelta(filename, node)
                     delta, deltabasename, origdeltabase, meta = deltaentry
                     size = meta.get(constants.METAKEYSIZE)
@@ -791,9 +788,9 @@
                     # If copyfrom == filename, it means the copy history
                     # went to come other file, then came back to this one, so we
                     # should continue processing it.
-                    if p1 != nullid and copyfrom != filename:
+                    if p1 != self.repo.nullid and copyfrom != filename:
                         dontprocess.add(p1)
-                    if p2 != nullid:
+                    if p2 != self.repo.nullid:
                         dontprocess.add(p2)
                     continue
 
@@ -814,9 +811,9 @@
         def parentfunc(node):
             p1, p2, linknode, copyfrom = ancestors[node]
             parents = []
-            if p1 != nullid:
+            if p1 != self.repo.nullid:
                 parents.append(p1)
-            if p2 != nullid:
+            if p2 != self.repo.nullid:
                 parents.append(p2)
             return parents
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/shallowbundle.py
--- a/hgext/remotefilelog/shallowbundle.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/shallowbundle.py	Mon Mar 29 01:52:06 2021 +0200
@@ -7,7 +7,7 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
-from mercurial.node import bin, hex, nullid
+from mercurial.node import bin, hex
 from mercurial import (
     bundlerepo,
     changegroup,
@@ -143,7 +143,7 @@
 
     def nodechunk(self, revlog, node, prevnode, linknode):
         prefix = b''
-        if prevnode == nullid:
+        if prevnode == revlog.nullid:
             delta = revlog.rawdata(node)
             prefix = mdiff.trivialdiffheader(len(delta))
         else:
@@ -245,7 +245,7 @@
     processed = set()
 
     def available(f, node, depf, depnode):
-        if depnode != nullid and (depf, depnode) not in processed:
+        if depnode != repo.nullid and (depf, depnode) not in processed:
             if not (depf, depnode) in revisiondatas:
                 # It's not in the changegroup, assume it's already
                 # in the repo
@@ -267,7 +267,7 @@
         dependents = [revisiondata[1], revisiondata[2], revisiondata[4]]
 
         for dependent in dependents:
-            if dependent == nullid or (f, dependent) in revisiondatas:
+            if dependent == repo.nullid or (f, dependent) in revisiondatas:
                 continue
             prefetchfiles.append((f, hex(dependent)))
 
@@ -306,7 +306,7 @@
                 continue
 
         for p in [p1, p2]:
-            if p != nullid:
+            if p != repo.nullid:
                 if not available(f, node, f, p):
                     continue
 
diff -r 5fa019ceb499 -r d55b71393907 hgext/remotefilelog/shallowrepo.py
--- a/hgext/remotefilelog/shallowrepo.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/remotefilelog/shallowrepo.py	Mon Mar 29 01:52:06 2021 +0200
@@ -9,7 +9,7 @@
 import os
 
 from mercurial.i18n import _
-from mercurial.node import hex, nullid, nullrev
+from mercurial.node import hex, nullrev
 from mercurial import (
     encoding,
     error,
@@ -206,8 +206,8 @@
                 m1 = ctx.p1().manifest()
                 files = []
                 for f in ctx.modified() + ctx.added():
-                    fparent1 = m1.get(f, nullid)
-                    if fparent1 != nullid:
+                    fparent1 = m1.get(f, self.nullid)
+                    if fparent1 != self.nullid:
                         files.append((f, hex(fparent1)))
                 self.fileservice.prefetch(files)
             return super(shallowrepository, self).commitctx(
diff -r 5fa019ceb499 -r d55b71393907 hgext/sqlitestore.py
--- a/hgext/sqlitestore.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/sqlitestore.py	Mon Mar 29 01:52:06 2021 +0200
@@ -52,7 +52,6 @@
 
 from mercurial.i18n import _
 from mercurial.node import (
-    nullid,
     nullrev,
     sha1nodeconstants,
     short,
@@ -366,12 +365,12 @@
                 )
 
             if p1rev == nullrev:
-                p1node = nullid
+                p1node = sha1nodeconstants.nullid
             else:
                 p1node = self._revtonode[p1rev]
 
             if p2rev == nullrev:
-                p2node = nullid
+                p2node = sha1nodeconstants.nullid
             else:
                 p2node = self._revtonode[p2rev]
 
@@ -400,7 +399,7 @@
         return iter(pycompat.xrange(len(self._revisions)))
 
     def hasnode(self, node):
-        if node == nullid:
+        if node == sha1nodeconstants.nullid:
             return False
 
         return node in self._nodetorev
@@ -411,8 +410,8 @@
         )
 
     def parents(self, node):
-        if node == nullid:
-            return nullid, nullid
+        if node == sha1nodeconstants.nullid:
+            return sha1nodeconstants.nullid, sha1nodeconstants.nullid
 
         if node not in self._revisions:
             raise error.LookupError(node, self._path, _(b'no node'))
@@ -431,7 +430,7 @@
         return entry.p1rev, entry.p2rev
 
     def rev(self, node):
-        if node == nullid:
+        if node == sha1nodeconstants.nullid:
             return nullrev
 
         if node not in self._nodetorev:
@@ -441,7 +440,7 @@
 
     def node(self, rev):
         if rev == nullrev:
-            return nullid
+            return sha1nodeconstants.nullid
 
         if rev not in self._revtonode:
             raise IndexError(rev)
@@ -485,7 +484,7 @@
     def heads(self, start=None, stop=None):
         if start is None and stop is None:
             if not len(self):
-                return [nullid]
+                return [sha1nodeconstants.nullid]
 
         startrev = self.rev(start) if start is not None else nullrev
         stoprevs = {self.rev(n) for n in stop or []}
@@ -529,7 +528,7 @@
         return len(self.revision(node))
 
     def revision(self, node, raw=False, _verifyhash=True):
-        if node in (nullid, nullrev):
+        if node in (sha1nodeconstants.nullid, nullrev):
             return b''
 
         if isinstance(node, int):
@@ -596,7 +595,7 @@
                 b'unhandled value for nodesorder: %s' % nodesorder
             )
 
-        nodes = [n for n in nodes if n != nullid]
+        nodes = [n for n in nodes if n != sha1nodeconstants.nullid]
 
         if not nodes:
             return
@@ -705,12 +704,12 @@
                 raise SQLiteStoreError(b'unhandled revision flag')
 
             if maybemissingparents:
-                if p1 != nullid and not self.hasnode(p1):
-                    p1 = nullid
+                if p1 != sha1nodeconstants.nullid and not self.hasnode(p1):
+                    p1 = sha1nodeconstants.nullid
                     storeflags |= FLAG_MISSING_P1
 
-                if p2 != nullid and not self.hasnode(p2):
-                    p2 = nullid
+                if p2 != sha1nodeconstants.nullid and not self.hasnode(p2):
+                    p2 = sha1nodeconstants.nullid
                     storeflags |= FLAG_MISSING_P2
 
             baserev = self.rev(deltabase)
@@ -736,7 +735,10 @@
                 # Possibly reset parents to make them proper.
                 entry = self._revisions[node]
 
-                if entry.flags & FLAG_MISSING_P1 and p1 != nullid:
+                if (
+                    entry.flags & FLAG_MISSING_P1
+                    and p1 != sha1nodeconstants.nullid
+                ):
                     entry.p1node = p1
                     entry.p1rev = self._nodetorev[p1]
                     entry.flags &= ~FLAG_MISSING_P1
@@ -746,7 +748,10 @@
                         (self._nodetorev[p1], entry.flags, entry.rid),
                     )
 
-                if entry.flags & FLAG_MISSING_P2 and p2 != nullid:
+                if (
+                    entry.flags & FLAG_MISSING_P2
+                    and p2 != sha1nodeconstants.nullid
+                ):
                     entry.p2node = p2
                     entry.p2rev = self._nodetorev[p2]
                     entry.flags &= ~FLAG_MISSING_P2
@@ -761,7 +766,7 @@
                 empty = False
                 continue
 
-            if deltabase == nullid:
+            if deltabase == sha1nodeconstants.nullid:
                 text = mdiff.patch(b'', delta)
                 storedelta = None
             else:
@@ -1012,7 +1017,7 @@
             assert revisiondata is not None
             deltabase = p1
 
-            if deltabase == nullid:
+            if deltabase == sha1nodeconstants.nullid:
                 delta = revisiondata
             else:
                 delta = mdiff.textdiff(
@@ -1021,7 +1026,7 @@
 
         # File index stores a pointer to its delta and the parent delta.
         # The parent delta is stored via a pointer to the fileindex PK.
-        if deltabase == nullid:
+        if deltabase == sha1nodeconstants.nullid:
             baseid = None
         else:
             baseid = self._revisions[deltabase].rid
@@ -1055,12 +1060,12 @@
 
         rev = len(self)
 
-        if p1 == nullid:
+        if p1 == sha1nodeconstants.nullid:
             p1rev = nullrev
         else:
             p1rev = self._nodetorev[p1]
 
-        if p2 == nullid:
+        if p2 == sha1nodeconstants.nullid:
             p2rev = nullrev
         else:
             p2rev = self._nodetorev[p2]
diff -r 5fa019ceb499 -r d55b71393907 hgext/transplant.py
--- a/hgext/transplant.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/transplant.py	Mon Mar 29 01:52:06 2021 +0200
@@ -22,7 +22,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     short,
 )
 from mercurial import (
@@ -134,6 +133,7 @@
 class transplanter(object):
     def __init__(self, ui, repo, opts):
         self.ui = ui
+        self.repo = repo
         self.path = repo.vfs.join(b'transplant')
         self.opener = vfsmod.vfs(self.path)
         self.transplants = transplants(
@@ -221,7 +221,7 @@
                         exchange.pull(repo, source.peer(), heads=[node])
 
                 skipmerge = False
-                if parents[1] != nullid:
+                if parents[1] != repo.nullid:
                     if not opts.get(b'parent'):
                         self.ui.note(
                             _(b'skipping merge changeset %d:%s\n')
@@ -516,7 +516,7 @@
     def parselog(self, fp):
         parents = []
         message = []
-        node = nullid
+        node = self.repo.nullid
         inmsg = False
         user = None
         date = None
@@ -568,7 +568,7 @@
         def matchfn(node):
             if self.applied(repo, node, root):
                 return False
-            if source.changelog.parents(node)[1] != nullid:
+            if source.changelog.parents(node)[1] != repo.nullid:
                 return False
             extra = source.changelog.read(node)[5]
             cnode = extra.get(b'transplant_source')
@@ -804,7 +804,7 @@
     tp = transplanter(ui, repo, opts)
 
     p1 = repo.dirstate.p1()
-    if len(repo) > 0 and p1 == nullid:
+    if len(repo) > 0 and p1 == repo.nullid:
         raise error.Abort(_(b'no revision checked out'))
     if opts.get(b'continue'):
         if not tp.canresume():
diff -r 5fa019ceb499 -r d55b71393907 hgext/uncommit.py
--- a/hgext/uncommit.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/hgext/uncommit.py	Mon Mar 29 01:52:06 2021 +0200
@@ -20,7 +20,6 @@
 from __future__ import absolute_import
 
 from mercurial.i18n import _
-from mercurial.node import nullid
 
 from mercurial import (
     cmdutil,
@@ -113,7 +112,7 @@
 
     new = context.memctx(
         repo,
-        parents=[base.node(), nullid],
+        parents=[base.node(), repo.nullid],
         text=message,
         files=files,
         filectxfn=filectxfn,
diff -r 5fa019ceb499 -r d55b71393907 mercurial/bookmarks.py
--- a/mercurial/bookmarks.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/bookmarks.py	Mon Mar 29 01:52:06 2021 +0200
@@ -15,7 +15,6 @@
     bin,
     hex,
     short,
-    wdirid,
 )
 from .pycompat import getattr
 from . import (
@@ -642,7 +641,7 @@
     binarydata = []
     for book, node in bookmarks:
         if not node:  # None or ''
-            node = wdirid
+            node = repo.nodeconstants.wdirid
         binarydata.append(_binaryentry.pack(node, len(book)))
         binarydata.append(book)
     return b''.join(binarydata)
@@ -674,7 +673,7 @@
         if len(bookmark) < length:
             if entry:
                 raise error.Abort(_(b'bad bookmark stream'))
-        if node == wdirid:
+        if node == repo.nodeconstants.wdirid:
             node = None
         books.append((bookmark, node))
     return books
diff -r 5fa019ceb499 -r d55b71393907 mercurial/branchmap.py
--- a/mercurial/branchmap.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/branchmap.py	Mon Mar 29 01:52:06 2021 +0200
@@ -12,7 +12,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from . import (
@@ -189,7 +188,7 @@
         self,
         repo,
         entries=(),
-        tipnode=nullid,
+        tipnode=None,
         tiprev=nullrev,
         filteredhash=None,
         closednodes=None,
@@ -200,7 +199,10 @@
         has a given node or not. If it's not provided, we assume that every node
         we have exists in changelog"""
         self._repo = repo
-        self.tipnode = tipnode
+        if tipnode is None:
+            self.tipnode = repo.nullid
+        else:
+            self.tipnode = tipnode
         self.tiprev = tiprev
         self.filteredhash = filteredhash
         # closednodes is a set of nodes that close their branch. If the branch
@@ -536,7 +538,7 @@
 
         if not self.validfor(repo):
             # cache key are not valid anymore
-            self.tipnode = nullid
+            self.tipnode = repo.nullid
             self.tiprev = nullrev
             for heads in self.iterheads():
                 tiprev = max(cl.rev(node) for node in heads)
diff -r 5fa019ceb499 -r d55b71393907 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/bundle2.py	Mon Mar 29 01:52:06 2021 +0200
@@ -158,7 +158,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     short,
 )
 from . import (
@@ -2576,7 +2575,7 @@
             fullnodes=commonnodes,
         )
         cgdata = packer.generate(
-            {nullid},
+            {repo.nullid},
             list(commonnodes),
             False,
             b'narrow_widen',
diff -r 5fa019ceb499 -r d55b71393907 mercurial/bundlerepo.py
--- a/mercurial/bundlerepo.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/bundlerepo.py	Mon Mar 29 01:52:06 2021 +0200
@@ -19,7 +19,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
 )
 
@@ -447,7 +446,9 @@
         return encoding.getcwd()  # always outside the repo
 
     # Check if parents exist in localrepo before setting
-    def setparents(self, p1, p2=nullid):
+    def setparents(self, p1, p2=None):
+        if p2 is None:
+            p2 = self.nullid
         p1rev = self.changelog.rev(p1)
         p2rev = self.changelog.rev(p2)
         msg = _(b"setting parent to node %s that only exists in the bundle\n")
diff -r 5fa019ceb499 -r d55b71393907 mercurial/changegroup.py
--- a/mercurial/changegroup.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/changegroup.py	Mon Mar 29 01:52:06 2021 +0200
@@ -15,7 +15,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -673,7 +672,7 @@
 
     if delta.delta is not None:
         prefix, data = b'', delta.delta
-    elif delta.basenode == nullid:
+    elif delta.basenode == repo.nullid:
         data = delta.revision
         prefix = mdiff.trivialdiffheader(len(data))
     else:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/changelog.py
--- a/mercurial/changelog.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/changelog.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,7 +11,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
 )
 from .thirdparty import attr
 
@@ -221,7 +220,7 @@
 
     def __new__(cls, cl, text, sidedata, cpsd):
         if not text:
-            return _changelogrevision(extra=_defaultextra, manifest=nullid)
+            return _changelogrevision(extra=_defaultextra, manifest=cl.nullid)
 
         self = super(changelogrevision, cls).__new__(cls)
         # We could return here and implement the following as an __init__.
diff -r 5fa019ceb499 -r d55b71393907 mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/cmdutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -15,7 +15,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -1097,7 +1096,7 @@
     'hint' is the usual hint given to Abort exception.
     """
 
-    if merge and repo.dirstate.p2() != nullid:
+    if merge and repo.dirstate.p2() != repo.nullid:
         raise error.StateError(_(b'outstanding uncommitted merge'), hint=hint)
     st = repo.status()
     if st.modified or st.added or st.removed or st.deleted:
@@ -2104,7 +2103,7 @@
     if parents:
         prev = parents[0]
     else:
-        prev = nullid
+        prev = repo.nullid
 
     fm.context(ctx=ctx)
     fm.plain(b'# HG changeset patch\n')
@@ -2967,7 +2966,7 @@
         ms.reset()
 
         # Reroute the working copy parent to the new changeset
-        repo.setparents(newid, nullid)
+        repo.setparents(newid, repo.nullid)
 
         # Fixing the dirstate because localrepo.commitctx does not update
         # it. This is rather convenient because we did not need to update
@@ -3322,7 +3321,7 @@
 
         # in case of merge, files that are actually added can be reported as
         # modified, we need to post process the result
-        if p2 != nullid:
+        if p2 != repo.nullid:
             mergeadd = set(dsmodified)
             for path in dsmodified:
                 if path in mf:
@@ -3593,7 +3592,7 @@
         # We're reverting to our parent. If possible, we'd like status
         # to report the file as clean. We have to use normallookup for
         # merges to avoid losing information about merged/dirty files.
-        if p2 != nullid:
+        if p2 != repo.nullid:
             normal = repo.dirstate.normallookup
         else:
             normal = repo.dirstate.normal
@@ -3690,7 +3689,7 @@
             repo.dirstate.add(f)
 
     normal = repo.dirstate.normallookup
-    if node == parent and p2 == nullid:
+    if node == parent and p2 == repo.nullid:
         normal = repo.dirstate.normal
     for f in actions[b'undelete'][0]:
         if interactive:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/commands.py
--- a/mercurial/commands.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/commands.py	Mon Mar 29 01:52:06 2021 +0200
@@ -15,10 +15,8 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
     short,
-    wdirhex,
     wdirrev,
 )
 from .pycompat import open
@@ -486,7 +484,7 @@
                     return b'%d ' % rev
 
         def formathex(h):
-            if h == wdirhex:
+            if h == repo.nodeconstants.wdirhex:
                 return b'%s+' % shorthex(hex(ctx.p1().node()))
             else:
                 return b'%s ' % shorthex(h)
@@ -809,9 +807,9 @@
         )
 
     p1, p2 = repo.changelog.parents(node)
-    if p1 == nullid:
+    if p1 == repo.nullid:
         raise error.InputError(_(b'cannot backout a change with no parents'))
-    if p2 != nullid:
+    if p2 != repo.nullid:
         if not opts.get(b'parent'):
             raise error.InputError(_(b'cannot backout a merge changeset'))
         p = repo.lookup(opts[b'parent'])
@@ -1085,7 +1083,7 @@
                 )
         else:
             node, p2 = repo.dirstate.parents()
-            if p2 != nullid:
+            if p2 != repo.nullid:
                 raise error.StateError(_(b'current bisect revision is a merge'))
         if rev:
             if not nodes:
@@ -4847,7 +4845,7 @@
 
     opts = pycompat.byteskwargs(opts)
     abort = opts.get(b'abort')
-    if abort and repo.dirstate.p2() == nullid:
+    if abort and repo.dirstate.p2() == repo.nullid:
         cmdutil.wrongtooltocontinue(repo, _(b'merge'))
     cmdutil.check_incompatible_arguments(opts, b'abort', [b'rev', b'preview'])
     if abort:
@@ -5072,7 +5070,7 @@
 
     displayer = logcmdutil.changesetdisplayer(ui, repo, opts)
     for n in p:
-        if n != nullid:
+        if n != repo.nullid:
             displayer.show(repo[n])
     displayer.close()
 
@@ -6105,7 +6103,7 @@
     with repo.wlock():
         ms = mergestatemod.mergestate.read(repo)
 
-        if not (ms.active() or repo.dirstate.p2() != nullid):
+        if not (ms.active() or repo.dirstate.p2() != repo.nullid):
             raise error.StateError(
                 _(b'resolve command not applicable when not merging')
             )
@@ -6223,7 +6221,7 @@
                     raise
 
         ms.commit()
-        branchmerge = repo.dirstate.p2() != nullid
+        branchmerge = repo.dirstate.p2() != repo.nullid
         mergestatemod.recordupdates(repo, ms.actions(), branchmerge, None)
 
         if not didwork and pats:
@@ -6315,7 +6313,7 @@
         opts[b"rev"] = cmdutil.finddate(ui, repo, opts[b"date"])
 
     parent, p2 = repo.dirstate.parents()
-    if not opts.get(b'rev') and p2 != nullid:
+    if not opts.get(b'rev') and p2 != repo.nullid:
         # revert after merge is a trap for new users (issue2915)
         raise error.InputError(
             _(b'uncommitted merge with no revision specified'),
@@ -6335,7 +6333,7 @@
         or opts.get(b'interactive')
     ):
         msg = _(b"no files or directories specified")
-        if p2 != nullid:
+        if p2 != repo.nullid:
             hint = _(
                 b"uncommitted merge, use --all to discard all changes,"
                 b" or 'hg update -C .' to abort the merge"
@@ -7396,7 +7394,7 @@
             for n in names:
                 if repo.tagtype(n) == b'global':
                     alltags = tagsmod.findglobaltags(ui, repo)
-                    if alltags[n][0] == nullid:
+                    if alltags[n][0] == repo.nullid:
                         raise error.InputError(
                             _(b"tag '%s' is already removed") % n
                         )
@@ -7423,7 +7421,7 @@
                     )
         if not opts.get(b'local'):
             p1, p2 = repo.dirstate.parents()
-            if p2 != nullid:
+            if p2 != repo.nullid:
                 raise error.StateError(_(b'uncommitted merge'))
             bheads = repo.branchheads()
             if not opts.get(b'force') and bheads and p1 not in bheads:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/commit.py
--- a/mercurial/commit.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/commit.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,7 +10,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
 )
 
@@ -277,10 +276,10 @@
     """
 
     fname = fctx.path()
-    fparent1 = manifest1.get(fname, nullid)
-    fparent2 = manifest2.get(fname, nullid)
+    fparent1 = manifest1.get(fname, repo.nullid)
+    fparent2 = manifest2.get(fname, repo.nullid)
     touched = None
-    if fparent1 == fparent2 == nullid:
+    if fparent1 == fparent2 == repo.nullid:
         touched = 'added'
 
     if isinstance(fctx, context.filectx):
@@ -291,9 +290,11 @@
         if node in [fparent1, fparent2]:
             repo.ui.debug(b'reusing %s filelog entry\n' % fname)
             if (
-                fparent1 != nullid and manifest1.flags(fname) != fctx.flags()
+                fparent1 != repo.nullid
+                and manifest1.flags(fname) != fctx.flags()
             ) or (
-                fparent2 != nullid and manifest2.flags(fname) != fctx.flags()
+                fparent2 != repo.nullid
+                and manifest2.flags(fname) != fctx.flags()
             ):
                 touched = 'modified'
             return node, touched
@@ -327,7 +328,9 @@
         newfparent = fparent2
 
         if manifest2:  # branch merge
-            if fparent2 == nullid or cnode is None:  # copied on remote side
+            if (
+                fparent2 == repo.nullid or cnode is None
+            ):  # copied on remote side
                 if cfname in manifest2:
                     cnode = manifest2[cfname]
                     newfparent = fparent1
@@ -346,7 +349,7 @@
             if includecopymeta:
                 meta[b"copy"] = cfname
                 meta[b"copyrev"] = hex(cnode)
-            fparent1, fparent2 = nullid, newfparent
+            fparent1, fparent2 = repo.nullid, newfparent
         else:
             repo.ui.warn(
                 _(
@@ -356,20 +359,20 @@
                 % (fname, cfname)
             )
 
-    elif fparent1 == nullid:
-        fparent1, fparent2 = fparent2, nullid
-    elif fparent2 != nullid:
+    elif fparent1 == repo.nullid:
+        fparent1, fparent2 = fparent2, repo.nullid
+    elif fparent2 != repo.nullid:
         if ms.active() and ms.extras(fname).get(b'filenode-source') == b'other':
-            fparent1, fparent2 = fparent2, nullid
+            fparent1, fparent2 = fparent2, repo.nullid
         elif ms.active() and ms.extras(fname).get(b'merged') != b'yes':
-            fparent1, fparent2 = fparent1, nullid
+            fparent1, fparent2 = fparent1, repo.nullid
         # is one parent an ancestor of the other?
         else:
             fparentancestors = flog.commonancestorsheads(fparent1, fparent2)
             if fparent1 in fparentancestors:
-                fparent1, fparent2 = fparent2, nullid
+                fparent1, fparent2 = fparent2, repo.nullid
             elif fparent2 in fparentancestors:
-                fparent2 = nullid
+                fparent2 = repo.nullid
 
     force_new_node = False
     # The file might have been deleted by merge code and user explicitly choose
@@ -384,9 +387,14 @@
         force_new_node = True
     # is the file changed?
     text = fctx.data()
-    if fparent2 != nullid or meta or flog.cmp(fparent1, text) or force_new_node:
+    if (
+        fparent2 != repo.nullid
+        or meta
+        or flog.cmp(fparent1, text)
+        or force_new_node
+    ):
         if touched is None:  # do not overwrite added
-            if fparent2 == nullid:
+            if fparent2 == repo.nullid:
                 touched = 'modified'
             else:
                 touched = 'merged'
diff -r 5fa019ceb499 -r d55b71393907 mercurial/context.py
--- a/mercurial/context.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/context.py	Mon Mar 29 01:52:06 2021 +0200
@@ -14,14 +14,9 @@
 
 from .i18n import _
 from .node import (
-    addednodeid,
     hex,
-    modifiednodeid,
-    nullid,
     nullrev,
     short,
-    wdirfilenodeids,
-    wdirhex,
 )
 from .pycompat import (
     getattr,
@@ -140,7 +135,7 @@
                 removed.append(fn)
             elif flag1 != flag2:
                 modified.append(fn)
-            elif node2 not in wdirfilenodeids:
+            elif node2 not in self._repo.nodeconstants.wdirfilenodeids:
                 # When comparing files between two commits, we save time by
                 # not comparing the file contents when the nodeids differ.
                 # Note that this means we incorrectly report a reverted change
@@ -737,7 +732,7 @@
             n2 = c2._parents[0]._node
         cahs = self._repo.changelog.commonancestorsheads(self._node, n2)
         if not cahs:
-            anc = nullid
+            anc = self._repo.nodeconstants.nullid
         elif len(cahs) == 1:
             anc = cahs[0]
         else:
@@ -1132,7 +1127,11 @@
         _path = self._path
         fl = self._filelog
         parents = self._filelog.parents(self._filenode)
-        pl = [(_path, node, fl) for node in parents if node != nullid]
+        pl = [
+            (_path, node, fl)
+            for node in parents
+            if node != self._repo.nodeconstants.nullid
+        ]
 
         r = fl.renamed(self._filenode)
         if r:
@@ -1556,12 +1555,12 @@
         return self._repo.dirstate[key] not in b"?r"
 
     def hex(self):
-        return wdirhex
+        return self._repo.nodeconstants.wdirhex
 
     @propertycache
     def _parents(self):
         p = self._repo.dirstate.parents()
-        if p[1] == nullid:
+        if p[1] == self._repo.nodeconstants.nullid:
             p = p[:-1]
         # use unfiltered repo to delay/avoid loading obsmarkers
         unfi = self._repo.unfiltered()
@@ -1572,7 +1571,9 @@
             for n in p
         ]
 
-    def setparents(self, p1node, p2node=nullid):
+    def setparents(self, p1node, p2node=None):
+        if p2node is None:
+            p2node = self._repo.nodeconstants.nullid
         dirstate = self._repo.dirstate
         with dirstate.parentchange():
             copies = dirstate.setparents(p1node, p2node)
@@ -1584,7 +1585,7 @@
                 for f in copies:
                     if f not in pctx and copies[f] in pctx:
                         dirstate.copy(copies[f], f)
-            if p2node == nullid:
+            if p2node == self._repo.nodeconstants.nullid:
                 for f, s in sorted(dirstate.copies().items()):
                     if f not in pctx and s not in pctx:
                         dirstate.copy(None, f)
@@ -1944,8 +1945,8 @@
 
         ff = self._flagfunc
         for i, l in (
-            (addednodeid, status.added),
-            (modifiednodeid, status.modified),
+            (self._repo.nodeconstants.addednodeid, status.added),
+            (self._repo.nodeconstants.modifiednodeid, status.modified),
         ):
             for f in l:
                 man[f] = i
@@ -2070,13 +2071,18 @@
         path = self.copysource()
         if not path:
             return None
-        return path, self._changectx._parents[0]._manifest.get(path, nullid)
+        return (
+            path,
+            self._changectx._parents[0]._manifest.get(
+                path, self._repo.nodeconstants.nullid
+            ),
+        )
 
     def parents(self):
         '''return parent filectxs, following copies if necessary'''
 
         def filenode(ctx, path):
-            return ctx._manifest.get(path, nullid)
+            return ctx._manifest.get(path, self._repo.nodeconstants.nullid)
 
         path = self._path
         fl = self._filelog
@@ -2094,7 +2100,7 @@
         return [
             self._parentfilectx(p, fileid=n, filelog=l)
             for p, n, l in pl
-            if n != nullid
+            if n != self._repo.nodeconstants.nullid
         ]
 
     def children(self):
@@ -2222,7 +2228,9 @@
         # ``overlayworkingctx`` (e.g. with --collapse).
         util.clearcachedproperty(self, b'_manifest')
 
-    def setparents(self, p1node, p2node=nullid):
+    def setparents(self, p1node, p2node=None):
+        if p2node is None:
+            p2node = self._repo.nodeconstants.nullid
         assert p1node == self._wrappedctx.node()
         self._parents = [self._wrappedctx, self._repo.unfiltered()[p2node]]
 
@@ -2248,10 +2256,10 @@
 
         flag = self._flagfunc
         for path in self.added():
-            man[path] = addednodeid
+            man[path] = self._repo.nodeconstants.addednodeid
             man.setflag(path, flag(path))
         for path in self.modified():
-            man[path] = modifiednodeid
+            man[path] = self._repo.nodeconstants.modifiednodeid
             man.setflag(path, flag(path))
         for path in self.removed():
             del man[path]
@@ -2827,7 +2835,7 @@
         )
         self._rev = None
         self._node = None
-        parents = [(p or nullid) for p in parents]
+        parents = [(p or self._repo.nodeconstants.nullid) for p in parents]
         p1, p2 = parents
         self._parents = [self._repo[p] for p in (p1, p2)]
         files = sorted(set(files))
@@ -2866,10 +2874,10 @@
         man = pctx.manifest().copy()
 
         for f in self._status.modified:
-            man[f] = modifiednodeid
+            man[f] = self._repo.nodeconstants.modifiednodeid
 
         for f in self._status.added:
-            man[f] = addednodeid
+            man[f] = self._repo.nodeconstants.addednodeid
 
         for f in self._status.removed:
             if f in man:
@@ -3006,12 +3014,12 @@
         # sanity check to ensure that the reused manifest parents are
         # manifests of our commit parents
         mp1, mp2 = self.manifestctx().parents
-        if p1 != nullid and p1.manifestnode() != mp1:
+        if p1 != self._repo.nodeconstants.nullid and p1.manifestnode() != mp1:
             raise RuntimeError(
                 r"can't reuse the manifest: its p1 "
                 r"doesn't match the new ctx p1"
             )
-        if p2 != nullid and p2.manifestnode() != mp2:
+        if p2 != self._repo.nodeconstants.nullid and p2.manifestnode() != mp2:
             raise RuntimeError(
                 r"can't reuse the manifest: "
                 r"its p2 doesn't match the new ctx p2"
diff -r 5fa019ceb499 -r d55b71393907 mercurial/copies.py
--- a/mercurial/copies.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/copies.py	Mon Mar 29 01:52:06 2021 +0200
@@ -12,10 +12,7 @@
 import os
 
 from .i18n import _
-from .node import (
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 
 from . import (
     match as matchmod,
@@ -579,7 +576,7 @@
             parents = fctx._filelog.parents(fctx._filenode)
             nb_parents = 0
             for n in parents:
-                if n != nullid:
+                if n != repo.nullid:
                     nb_parents += 1
             return nb_parents >= 2
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/debugcommands.py	Mon Mar 29 01:52:06 2021 +0200
@@ -30,7 +30,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -1667,7 +1666,7 @@
         node = r.node(i)
         pp = r.parents(node)
         ui.write(b"\t%d -> %d\n" % (r.rev(pp[0]), i))
-        if pp[1] != nullid:
+        if pp[1] != repo.nullid:
             ui.write(b"\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write(b"}\n")
 
@@ -1675,7 +1674,7 @@
 @command(b'debugindexstats', [])
 def debugindexstats(ui, repo):
     """show stats related to the changelog index"""
-    repo.changelog.shortest(nullid, 1)
+    repo.changelog.shortest(repo.nullid, 1)
     index = repo.changelog.index
     if not util.safehasattr(index, b'stats'):
         raise error.Abort(_(b'debugindexstats only works with native code'))
@@ -2425,7 +2424,7 @@
             # arbitrary node identifiers, possibly not present in the
             # local repository.
             n = bin(s)
-            if len(n) != len(nullid):
+            if len(n) != repo.nodeconstants.nodelen:
                 raise TypeError()
             return n
         except TypeError:
@@ -3328,7 +3327,7 @@
             try:
                 pp = r.parents(node)
             except Exception:
-                pp = [nullid, nullid]
+                pp = [repo.nullid, repo.nullid]
             if ui.verbose:
                 ui.write(
                     b"% 6d % 9d % 7d % 7d %s %s %s\n"
@@ -3742,7 +3741,9 @@
         for n in chlist:
             if limit is not None and count >= limit:
                 break
-            parents = [True for p in other.changelog.parents(n) if p != nullid]
+            parents = [
+                True for p in other.changelog.parents(n) if p != repo.nullid
+            ]
             if opts.get(b"no_merges") and len(parents) == 2:
                 continue
             count += 1
diff -r 5fa019ceb499 -r d55b71393907 mercurial/dirstate.py
--- a/mercurial/dirstate.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/dirstate.py	Mon Mar 29 01:52:06 2021 +0200
@@ -14,7 +14,6 @@
 import stat
 
 from .i18n import _
-from .node import nullid
 from .pycompat import delattr
 
 from hgdemandimport import tracing
@@ -314,7 +313,7 @@
     def branch(self):
         return encoding.tolocal(self._branch)
 
-    def setparents(self, p1, p2=nullid):
+    def setparents(self, p1, p2=None):
         """Set dirstate parents to p1 and p2.
 
         When moving from two parents to one, 'm' merged entries a
@@ -323,6 +322,8 @@
 
         See localrepo.setparents()
         """
+        if p2 is None:
+            p2 = self._nodeconstants.nullid
         if self._parentwriters == 0:
             raise ValueError(
                 b"cannot set dirstate parent outside of "
@@ -335,7 +336,10 @@
             self._origpl = self._pl
         self._map.setparents(p1, p2)
         copies = {}
-        if oldp2 != nullid and p2 == nullid:
+        if (
+            oldp2 != self._nodeconstants.nullid
+            and p2 == self._nodeconstants.nullid
+        ):
             candidatefiles = self._map.nonnormalset.union(
                 self._map.otherparentset
             )
@@ -459,7 +463,7 @@
 
     def normallookup(self, f):
         '''Mark a file normal, but possibly dirty.'''
-        if self._pl[1] != nullid:
+        if self._pl[1] != self._nodeconstants.nullid:
             # if there is a merge going on and the file was either
             # in state 'm' (-1) or coming from other parent (-2) before
             # being removed, restore that state.
@@ -481,7 +485,7 @@
 
     def otherparent(self, f):
         '''Mark as coming from the other parent, always dirty.'''
-        if self._pl[1] == nullid:
+        if self._pl[1] == self._nodeconstants.nullid:
             raise error.Abort(
                 _(b"setting %r to other parent only allowed in merges") % f
             )
@@ -503,7 +507,7 @@
         self._dirty = True
         oldstate = self[f]
         size = 0
-        if self._pl[1] != nullid:
+        if self._pl[1] != self._nodeconstants.nullid:
             entry = self._map.get(f)
             if entry is not None:
                 # backup the previous state
@@ -519,7 +523,7 @@
 
     def merge(self, f):
         '''Mark a file merged.'''
-        if self._pl[1] == nullid:
+        if self._pl[1] == self._nodeconstants.nullid:
             return self.normallookup(f)
         return self.otherparent(f)
 
@@ -638,7 +642,7 @@
 
         if self._origpl is None:
             self._origpl = self._pl
-        self._map.setparents(parent, nullid)
+        self._map.setparents(parent, self._nodeconstants.nullid)
 
         for f in to_lookup:
             self.normallookup(f)
@@ -1459,7 +1463,7 @@
     def clear(self):
         self._map.clear()
         self.copymap.clear()
-        self.setparents(nullid, nullid)
+        self.setparents(self._nodeconstants.nullid, self._nodeconstants.nullid)
         util.clearcachedproperty(self, b"_dirs")
         util.clearcachedproperty(self, b"_alldirs")
         util.clearcachedproperty(self, b"filefoldmap")
@@ -1636,7 +1640,10 @@
                     st[self._nodelen : 2 * self._nodelen],
                 )
             elif l == 0:
-                self._parents = (nullid, nullid)
+                self._parents = (
+                    self._nodeconstants.nullid,
+                    self._nodeconstants.nullid,
+                )
             else:
                 raise error.Abort(
                     _(b'working directory state appears damaged!')
@@ -1794,7 +1801,9 @@
         def clear(self):
             self._rustmap.clear()
             self._inner_rustmap.clear()
-            self.setparents(nullid, nullid)
+            self.setparents(
+                self._nodeconstants.nullid, self._nodeconstants.nullid
+            )
             util.clearcachedproperty(self, b"_dirs")
             util.clearcachedproperty(self, b"_alldirs")
             util.clearcachedproperty(self, b"dirfoldmap")
diff -r 5fa019ceb499 -r d55b71393907 mercurial/discovery.py
--- a/mercurial/discovery.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/discovery.py	Mon Mar 29 01:52:06 2021 +0200
@@ -12,7 +12,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     short,
 )
 
@@ -107,7 +106,7 @@
         if missingroots:
             discbases = []
             for n in missingroots:
-                discbases.extend([p for p in cl.parents(n) if p != nullid])
+                discbases.extend([p for p in cl.parents(n) if p != repo.nullid])
             # TODO remove call to nodesbetween.
             # TODO populate attributes on outgoing instance instead of setting
             # discbases.
@@ -116,7 +115,7 @@
             ancestorsof = heads
             commonheads = [n for n in discbases if n not in included]
         elif not commonheads:
-            commonheads = [nullid]
+            commonheads = [repo.nullid]
         self.commonheads = commonheads
         self.ancestorsof = ancestorsof
         self._revlog = cl
@@ -381,7 +380,7 @@
     # - a local outgoing head descended from update
     # - a remote head that's known locally and not
     #   ancestral to an outgoing head
-    if remoteheads == [nullid]:
+    if remoteheads == [repo.nullid]:
         # remote is empty, nothing to check.
         return
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/exchange.py
--- a/mercurial/exchange.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/exchange.py	Mon Mar 29 01:52:06 2021 +0200
@@ -13,7 +13,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     nullrev,
 )
 from . import (
@@ -164,7 +163,7 @@
         hasnode = cl.hasnode
         common = [n for n in common if hasnode(n)]
     else:
-        common = [nullid]
+        common = [repo.nullid]
     if not heads:
         heads = cl.heads()
     return discovery.outgoing(repo, common, heads)
@@ -1839,7 +1838,7 @@
     if (
         pullop.remote.capable(b'clonebundles')
         and pullop.heads is None
-        and list(pullop.common) == [nullid]
+        and list(pullop.common) == [pullop.repo.nullid]
     ):
         kwargs[b'cbattempted'] = pullop.clonebundleattempted
 
@@ -1849,7 +1848,7 @@
         pullop.repo.ui.status(_(b"no changes found\n"))
         pullop.cgresult = 0
     else:
-        if pullop.heads is None and list(pullop.common) == [nullid]:
+        if pullop.heads is None and list(pullop.common) == [pullop.repo.nullid]:
             pullop.repo.ui.status(_(b"requesting all changes\n"))
     if obsolete.isenabled(pullop.repo, obsolete.exchangeopt):
         remoteversions = bundle2.obsmarkersversion(pullop.remotebundle2caps)
@@ -1920,7 +1919,7 @@
         pullop.cgresult = 0
         return
     tr = pullop.gettransaction()
-    if pullop.heads is None and list(pullop.common) == [nullid]:
+    if pullop.heads is None and list(pullop.common) == [pullop.repo.nullid]:
         pullop.repo.ui.status(_(b"requesting all changes\n"))
     elif pullop.heads is None and pullop.remote.capable(b'changegroupsubset'):
         # issue1320, avoid a race if remote changed after discovery
diff -r 5fa019ceb499 -r d55b71393907 mercurial/exchangev2.py
--- a/mercurial/exchangev2.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/exchangev2.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,10 +11,7 @@
 import weakref
 
 from .i18n import _
-from .node import (
-    nullid,
-    short,
-)
+from .node import short
 from . import (
     bookmarks,
     error,
@@ -304,7 +301,7 @@
         if set(remoteheads).issubset(common):
             fetch = []
 
-    common.discard(nullid)
+    common.discard(repo.nullid)
 
     return common, fetch, remoteheads
 
@@ -413,7 +410,7 @@
                 # Linknode is always itself for changesets.
                 cset[b'node'],
                 # We always send full revisions. So delta base is not set.
-                nullid,
+                repo.nullid,
                 mdiff.trivialdiffheader(len(data)) + data,
                 # Flags not yet supported.
                 0,
@@ -478,7 +475,7 @@
                 basenode = manifest[b'deltabasenode']
                 delta = extrafields[b'delta']
             elif b'revision' in extrafields:
-                basenode = nullid
+                basenode = repo.nullid
                 revision = extrafields[b'revision']
                 delta = mdiff.trivialdiffheader(len(revision)) + revision
             else:
@@ -610,7 +607,7 @@
                 basenode = filerevision[b'deltabasenode']
                 delta = extrafields[b'delta']
             elif b'revision' in extrafields:
-                basenode = nullid
+                basenode = repo.nullid
                 revision = extrafields[b'revision']
                 delta = mdiff.trivialdiffheader(len(revision)) + revision
             else:
@@ -705,7 +702,7 @@
                 basenode = filerevision[b'deltabasenode']
                 delta = extrafields[b'delta']
             elif b'revision' in extrafields:
-                basenode = nullid
+                basenode = repo.nullid
                 revision = extrafields[b'revision']
                 delta = mdiff.trivialdiffheader(len(revision)) + revision
             else:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/filelog.py
--- a/mercurial/filelog.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/filelog.py	Mon Mar 29 01:52:06 2021 +0200
@@ -8,10 +8,7 @@
 from __future__ import absolute_import
 
 from .i18n import _
-from .node import (
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from . import (
     error,
     revlog,
@@ -42,7 +39,7 @@
         return self._revlog.__iter__()
 
     def hasnode(self, node):
-        if node in (nullid, nullrev):
+        if node in (self.nullid, nullrev):
             return False
 
         try:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/filemerge.py
--- a/mercurial/filemerge.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/filemerge.py	Mon Mar 29 01:52:06 2021 +0200
@@ -15,7 +15,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
     short,
 )
 from .pycompat import (
@@ -111,7 +110,7 @@
         return None
 
     def filenode(self):
-        return nullid
+        return self._ctx.repo().nullid
 
     _customcmp = True
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/hg.py
--- a/mercurial/hg.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/hg.py	Mon Mar 29 01:52:06 2021 +0200
@@ -16,8 +16,7 @@
 from .i18n import _
 from .node import (
     hex,
-    nullhex,
-    nullid,
+    sha1nodeconstants,
     short,
 )
 from .pycompat import getattr
@@ -772,7 +771,7 @@
                             },
                         ).result()
 
-                    if rootnode != nullid:
+                    if rootnode != sha1nodeconstants.nullid:
                         sharepath = os.path.join(sharepool, hex(rootnode))
                     else:
                         ui.status(
@@ -883,7 +882,9 @@
             # we need to re-init the repo after manually copying the data
             # into it
             destpeer = peer(srcrepo, peeropts, dest)
-            srcrepo.hook(b'outgoing', source=b'clone', node=nullhex)
+            srcrepo.hook(
+                b'outgoing', source=b'clone', node=srcrepo.nodeconstants.nullhex
+            )
         else:
             try:
                 # only pass ui when no srcrepo
@@ -1329,7 +1330,9 @@
         for n in chlist:
             if limit is not None and count >= limit:
                 break
-            parents = [p for p in other.changelog.parents(n) if p != nullid]
+            parents = [
+                p for p in other.changelog.parents(n) if p != repo.nullid
+            ]
             if opts.get(b'no_merges') and len(parents) == 2:
                 continue
             count += 1
@@ -1406,7 +1409,7 @@
     for n in revs:
         if limit is not None and count >= limit:
             break
-        parents = [p for p in cl.parents(n) if p != nullid]
+        parents = [p for p in cl.parents(n) if p != repo.nullid]
         if no_merges and len(parents) == 2:
             continue
         count += 1
diff -r 5fa019ceb499 -r d55b71393907 mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/hgweb/webutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -14,7 +14,7 @@
 import re
 
 from ..i18n import _
-from ..node import hex, nullid, short
+from ..node import hex, short
 from ..pycompat import setattr
 
 from .common import (
@@ -220,7 +220,7 @@
 def _siblings(siblings=None, hiderev=None):
     if siblings is None:
         siblings = []
-    siblings = [s for s in siblings if s.node() != nullid]
+    siblings = [s for s in siblings if s.node() != s.repo().nullid]
     if len(siblings) == 1 and siblings[0].rev() == hiderev:
         siblings = []
     return templateutil.mappinggenerator(_ctxsgen, args=(siblings,))
@@ -316,12 +316,16 @@
         yield {name: t}
 
 
-def showtag(repo, t1, node=nullid):
+def showtag(repo, t1, node=None):
+    if node is None:
+        node = repo.nullid
     args = (repo.nodetags, node, b'tag')
     return templateutil.mappinggenerator(_nodenamesgen, args=args, name=t1)
 
 
-def showbookmark(repo, t1, node=nullid):
+def showbookmark(repo, t1, node=None):
+    if node is None:
+        node = repo.nullid
     args = (repo.nodebookmarks, node, b'bookmark')
     return templateutil.mappinggenerator(_nodenamesgen, args=args, name=t1)
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/interfaces/dirstate.py
--- a/mercurial/interfaces/dirstate.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/interfaces/dirstate.py	Mon Mar 29 01:52:06 2021 +0200
@@ -2,8 +2,6 @@
 
 import contextlib
 
-from .. import node as nodemod
-
 from . import util as interfaceutil
 
 
@@ -97,7 +95,7 @@
     def branch():
         pass
 
-    def setparents(p1, p2=nodemod.nullid):
+    def setparents(p1, p2=None):
         """Set dirstate parents to p1 and p2.
 
         When moving from two parents to one, 'm' merged entries a
diff -r 5fa019ceb499 -r d55b71393907 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/localrepo.py	Mon Mar 29 01:52:06 2021 +0200
@@ -19,7 +19,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     sha1nodeconstants,
     short,
@@ -1702,7 +1701,7 @@
                     _(b"warning: ignoring unknown working parent %s!\n")
                     % short(node)
                 )
-            return nullid
+            return self.nullid
 
     @storecache(narrowspec.FILENAME)
     def narrowpats(self):
@@ -1753,9 +1752,9 @@
     @unfilteredpropertycache
     def _quick_access_changeid_null(self):
         return {
-            b'null': (nullrev, nullid),
-            nullrev: (nullrev, nullid),
-            nullid: (nullrev, nullid),
+            b'null': (nullrev, self.nodeconstants.nullid),
+            nullrev: (nullrev, self.nodeconstants.nullid),
+            self.nullid: (nullrev, self.nullid),
         }
 
     @unfilteredpropertycache
@@ -1765,7 +1764,7 @@
         quick = self._quick_access_changeid_null.copy()
         cl = self.unfiltered().changelog
         for node in self.dirstate.parents():
-            if node == nullid:
+            if node == self.nullid:
                 continue
             rev = cl.index.get_rev(node)
             if rev is None:
@@ -1785,7 +1784,7 @@
                 quick[r] = pair
                 quick[n] = pair
         p1node = self.dirstate.p1()
-        if p1node != nullid:
+        if p1node != self.nullid:
             quick[b'.'] = quick[p1node]
         return quick
 
@@ -2037,7 +2036,7 @@
         # local encoding.
         tags = {}
         for (name, (node, hist)) in pycompat.iteritems(alltags):
-            if node != nullid:
+            if node != self.nullid:
                 tags[encoding.tolocal(name)] = node
         tags[b'tip'] = self.changelog.tip()
         tagtypes = {
@@ -2161,7 +2160,9 @@
     def wjoin(self, f, *insidef):
         return self.vfs.reljoin(self.root, f, *insidef)
 
-    def setparents(self, p1, p2=nullid):
+    def setparents(self, p1, p2=None):
+        if p2 is None:
+            p2 = self.nullid
         self[None].setparents(p1, p2)
         self._quick_access_changeid_invalidate()
 
@@ -3094,7 +3095,7 @@
                 subrepoutil.writestate(self, newstate)
 
             p1, p2 = self.dirstate.parents()
-            hookp1, hookp2 = hex(p1), (p2 != nullid and hex(p2) or b'')
+            hookp1, hookp2 = hex(p1), (p2 != self.nullid and hex(p2) or b'')
             try:
                 self.hook(
                     b"precommit", throw=True, parent1=hookp1, parent2=hookp2
@@ -3267,7 +3268,7 @@
             t = n
             while True:
                 p = self.changelog.parents(n)
-                if p[1] != nullid or p[0] == nullid:
+                if p[1] != self.nullid or p[0] == self.nullid:
                     b.append((t, n, p[0], p[1]))
                     break
                 n = p[0]
@@ -3280,7 +3281,7 @@
             n, l, i = top, [], 0
             f = 1
 
-            while n != bottom and n != nullid:
+            while n != bottom and n != self.nullid:
                 p = self.changelog.parents(n)[0]
                 if i == f:
                     l.append(n)
diff -r 5fa019ceb499 -r d55b71393907 mercurial/logcmdutil.py
--- a/mercurial/logcmdutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/logcmdutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -12,12 +12,7 @@
 import posixpath
 
 from .i18n import _
-from .node import (
-    nullid,
-    nullrev,
-    wdirid,
-    wdirrev,
-)
+from .node import nullrev, wdirrev
 
 from .thirdparty import attr
 
@@ -357,7 +352,7 @@
         if self.ui.debugflag:
             mnode = ctx.manifestnode()
             if mnode is None:
-                mnode = wdirid
+                mnode = self.repo.nodeconstants.wdirid
                 mrev = wdirrev
             else:
                 mrev = self.repo.manifestlog.rev(mnode)
@@ -505,7 +500,11 @@
         )
 
         if self.ui.debugflag or b'manifest' in datahint:
-            fm.data(manifest=fm.hexfunc(ctx.manifestnode() or wdirid))
+            fm.data(
+                manifest=fm.hexfunc(
+                    ctx.manifestnode() or self.repo.nodeconstants.wdirid
+                )
+            )
         if self.ui.debugflag or b'extra' in datahint:
             fm.data(extra=fm.formatdict(ctx.extra()))
 
@@ -991,7 +990,7 @@
     """Return the initial set of revisions to be filtered or followed"""
     if wopts.revspec:
         revs = scmutil.revrange(repo, wopts.revspec)
-    elif wopts.follow and repo.dirstate.p1() == nullid:
+    elif wopts.follow and repo.dirstate.p1() == repo.nullid:
         revs = smartset.baseset()
     elif wopts.follow:
         revs = repo.revs(b'.')
diff -r 5fa019ceb499 -r d55b71393907 mercurial/manifest.py
--- a/mercurial/manifest.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/manifest.py	Mon Mar 29 01:52:06 2021 +0200
@@ -16,7 +16,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from .pycompat import getattr
@@ -795,7 +794,7 @@
     def __init__(self, nodeconstants, dir=b'', text=b''):
         self._dir = dir
         self.nodeconstants = nodeconstants
-        self._node = nullid
+        self._node = self.nodeconstants.nullid
         self._loadfunc = _noop
         self._copyfunc = _noop
         self._dirty = False
@@ -1391,7 +1390,7 @@
                 continue
             subp1 = getnode(m1, d)
             subp2 = getnode(m2, d)
-            if subp1 == nullid:
+            if subp1 == self.nodeconstants.nullid:
                 subp1, subp2 = subp2, subp1
             writesubtree(subm, subp1, subp2, match)
 
@@ -1994,7 +1993,7 @@
             else:
                 m = manifestctx(self, node)
 
-        if node != nullid:
+        if node != self.nodeconstants.nullid:
             mancache = self._dirmancache.get(tree)
             if not mancache:
                 mancache = util.lrucachedict(self._cachesize)
@@ -2082,7 +2081,7 @@
 
     def read(self):
         if self._data is None:
-            if self._node == nullid:
+            if self._node == self._manifestlog.nodeconstants.nullid:
                 self._data = manifestdict()
             else:
                 store = self._storage()
@@ -2188,7 +2187,7 @@
     def read(self):
         if self._data is None:
             store = self._storage()
-            if self._node == nullid:
+            if self._node == self._manifestlog.nodeconstants.nullid:
                 self._data = treemanifest(self._manifestlog.nodeconstants)
             # TODO accessing non-public API
             elif store._treeondisk:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/merge.py
--- a/mercurial/merge.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/merge.py	Mon Mar 29 01:52:06 2021 +0200
@@ -13,12 +13,7 @@
 import struct
 
 from .i18n import _
-from .node import (
-    addednodeid,
-    modifiednodeid,
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from .thirdparty import attr
 from .utils import stringutil
 from . import (
@@ -779,7 +774,7 @@
         # to flag the change. If wctx is a committed revision, we shouldn't
         # care for the dirty state of the working directory.
         if any(wctx.sub(s).dirty() for s in wctx.substate):
-            m1[b'.hgsubstate'] = modifiednodeid
+            m1[b'.hgsubstate'] = repo.nodeconstants.modifiednodeid
 
     # Don't use m2-vs-ma optimization if:
     # - ma is the same as m1 or m2, which we're just going to diff again later
@@ -944,7 +939,7 @@
                             mresult.addcommitinfo(
                                 f, b'merge-removal-candidate', b'yes'
                             )
-                elif n1 == addednodeid:
+                elif n1 == repo.nodeconstants.addednodeid:
                     # This file was locally added. We should forget it instead of
                     # deleting it.
                     mresult.addfile(
@@ -1785,7 +1780,7 @@
     if (
         fsmonitorwarning
         and not fsmonitorenabled
-        and p1node == nullid
+        and p1node == repo.nullid
         and num_gets >= fsmonitorthreshold
         and pycompat.sysplatform.startswith((b'linux', b'darwin'))
     ):
@@ -1913,7 +1908,7 @@
         else:
             if repo.ui.configlist(b'merge', b'preferancestor') == [b'*']:
                 cahs = repo.changelog.commonancestorsheads(p1.node(), p2.node())
-                pas = [repo[anc] for anc in (sorted(cahs) or [nullid])]
+                pas = [repo[anc] for anc in (sorted(cahs) or [repo.nullid])]
             else:
                 pas = [p1.ancestor(p2, warn=branchmerge)]
 
@@ -2112,7 +2107,7 @@
 
         ### apply phase
         if not branchmerge:  # just jump to the new rev
-            fp1, fp2, xp1, xp2 = fp2, nullid, xp2, b''
+            fp1, fp2, xp1, xp2 = fp2, repo.nullid, xp2, b''
         # If we're doing a partial update, we need to skip updating
         # the dirstate.
         always = matcher is None or matcher.always()
@@ -2281,14 +2276,14 @@
     if keepconflictparent and stats.unresolvedcount:
         pother = ctx.node()
     else:
-        pother = nullid
+        pother = repo.nullid
         parents = ctx.parents()
         if keepparent and len(parents) == 2 and base in parents:
             parents.remove(base)
             pother = parents[0].node()
     # Never set both parents equal to each other
     if pother == pctx.node():
-        pother = nullid
+        pother = repo.nullid
 
     if wctx.isinmemory():
         wctx.setparents(pctx.node(), pother)
diff -r 5fa019ceb499 -r d55b71393907 mercurial/mergestate.py
--- a/mercurial/mergestate.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/mergestate.py	Mon Mar 29 01:52:06 2021 +0200
@@ -9,7 +9,6 @@
 from .node import (
     bin,
     hex,
-    nullhex,
     nullrev,
 )
 from . import (
@@ -32,7 +31,7 @@
 
 
 def _filectxorabsent(hexnode, ctx, f):
-    if hexnode == nullhex:
+    if hexnode == ctx.repo().nodeconstants.nullhex:
         return filemerge.absentfilectx(ctx, f)
     else:
         return ctx[f]
@@ -248,7 +247,7 @@
         note: also write the local version to the `.hg/merge` directory.
         """
         if fcl.isabsent():
-            localkey = nullhex
+            localkey = self._repo.nodeconstants.nullhex
         else:
             localkey = mergestate.getlocalkey(fcl.path())
             self._make_backup(fcl, localkey)
@@ -354,7 +353,7 @@
                 flags = flo
         if preresolve:
             # restore local
-            if localkey != nullhex:
+            if localkey != self._repo.nodeconstants.nullhex:
                 self._restore_backup(wctx[dfile], localkey, flags)
             else:
                 wctx[dfile].remove(ignoremissing=True)
@@ -658,7 +657,10 @@
                 records.append(
                     (RECORD_PATH_CONFLICT, b'\0'.join([filename] + v))
                 )
-            elif v[1] == nullhex or v[6] == nullhex:
+            elif (
+                v[1] == self._repo.nodeconstants.nullhex
+                or v[6] == self._repo.nodeconstants.nullhex
+            ):
                 # Change/Delete or Delete/Change conflicts. These are stored in
                 # 'C' records. v[1] is the local file, and is nullhex when the
                 # file is deleted locally ('dc'). v[6] is the remote file, and
diff -r 5fa019ceb499 -r d55b71393907 mercurial/metadata.py
--- a/mercurial/metadata.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/metadata.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,10 +11,7 @@
 import multiprocessing
 import struct
 
-from .node import (
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from . import (
     error,
     pycompat,
@@ -617,7 +614,7 @@
         if f in ctx:
             fctx = ctx[f]
             parents = fctx._filelog.parents(fctx._filenode)
-            if parents[1] != nullid:
+            if parents[1] != ctx.repo().nullid:
                 merged.append(f)
     return merged
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/obsolete.py
--- a/mercurial/obsolete.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/obsolete.py	Mon Mar 29 01:52:06 2021 +0200
@@ -73,11 +73,14 @@
 import struct
 
 from .i18n import _
+from .node import (
+    bin,
+    hex,
+)
 from .pycompat import getattr
 from .node import (
     bin,
     hex,
-    nullid,
 )
 from . import (
     encoding,
@@ -526,14 +529,14 @@
                 children.setdefault(p, set()).add(mark)
 
 
-def _checkinvalidmarkers(markers):
+def _checkinvalidmarkers(repo, markers):
     """search for marker with invalid data and raise error if needed
 
     Exist as a separated function to allow the evolve extension for a more
     subtle handling.
     """
     for mark in markers:
-        if nullid in mark[1]:
+        if repo.nullid in mark[1]:
             raise error.Abort(
                 _(
                     b'bad obsolescence marker detected: '
@@ -727,7 +730,7 @@
             return []
         self._version, markers = _readmarkers(data)
         markers = list(markers)
-        _checkinvalidmarkers(markers)
+        _checkinvalidmarkers(self.repo, markers)
         return markers
 
     @propertycache
@@ -761,7 +764,7 @@
             _addpredecessors(self.predecessors, markers)
         if self._cached('children'):
             _addchildren(self.children, markers)
-        _checkinvalidmarkers(markers)
+        _checkinvalidmarkers(self.repo, markers)
 
     def relevantmarkers(self, nodes):
         """return a set of all obsolescence markers relevant to a set of nodes.
diff -r 5fa019ceb499 -r d55b71393907 mercurial/patch.py
--- a/mercurial/patch.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/patch.py	Mon Mar 29 01:52:06 2021 +0200
@@ -20,7 +20,7 @@
 from .i18n import _
 from .node import (
     hex,
-    nullhex,
+    sha1nodeconstants,
     short,
 )
 from .pycompat import open
@@ -3100,8 +3100,8 @@
 
     ctx1, fctx1, path1, flag1, content1, date1 = data1
     ctx2, fctx2, path2, flag2, content2, date2 = data2
-    index1 = _gitindex(content1) if path1 in ctx1 else nullhex
-    index2 = _gitindex(content2) if path2 in ctx2 else nullhex
+    index1 = _gitindex(content1) if path1 in ctx1 else sha1nodeconstants.nullhex
+    index2 = _gitindex(content2) if path2 in ctx2 else sha1nodeconstants.nullhex
     if binary and opts.git and not opts.nobinary:
         text = mdiff.b85diff(content1, content2)
         if text:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/phases.py
--- a/mercurial/phases.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/phases.py	Mon Mar 29 01:52:06 2021 +0200
@@ -109,7 +109,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
     wdirrev,
@@ -862,7 +861,7 @@
         node = bin(nhex)
         phase = int(phase)
         if phase == public:
-            if node != nullid:
+            if node != repo.nullid:
                 repo.ui.warn(
                     _(
                         b'ignoring inconsistent public root'
@@ -919,10 +918,10 @@
     rev = cl.index.get_rev
     if not roots:
         return heads
-    if not heads or heads == [nullid]:
+    if not heads or heads == [repo.nullid]:
         return []
     # The logic operated on revisions, convert arguments early for convenience
-    new_heads = {rev(n) for n in heads if n != nullid}
+    new_heads = {rev(n) for n in heads if n != repo.nullid}
     roots = [rev(n) for n in roots]
     # compute the area we need to remove
     affected_zone = repo.revs(b"(%ld::%ld)", roots, new_heads)
diff -r 5fa019ceb499 -r d55b71393907 mercurial/pure/parsers.py
--- a/mercurial/pure/parsers.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/pure/parsers.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,7 +10,10 @@
 import struct
 import zlib
 
-from ..node import nullid, nullrev
+from ..node import (
+    nullrev,
+    sha1nodeconstants,
+)
 from .. import (
     pycompat,
     util,
@@ -50,7 +53,7 @@
     # Size of a C long int, platform independent
     int_size = struct.calcsize(b'>i')
     # An empty index entry, used as a default value to be overridden, or nullrev
-    null_item = (0, 0, 0, -1, -1, -1, -1, nullid)
+    null_item = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid)
 
     @util.propertycache
     def entry_size(self):
@@ -64,7 +67,7 @@
 
     @util.propertycache
     def _nodemap(self):
-        nodemap = nodemaputil.NodeMap({nullid: nullrev})
+        nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         for r in range(0, len(self)):
             n = self[r][7]
             nodemap[n] = r
@@ -246,7 +249,7 @@
 
 class Index2Mixin(object):
     index_format = revlog_constants.INDEX_ENTRY_V2
-    null_item = (0, 0, 0, -1, -1, -1, -1, nullid, 0, 0)
+    null_item = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid, 0, 0)
 
     def replace_sidedata_info(self, i, sidedata_offset, sidedata_length):
         """
diff -r 5fa019ceb499 -r d55b71393907 mercurial/revlog.py
--- a/mercurial/revlog.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/revlog.py	Mon Mar 29 01:52:06 2021 +0200
@@ -26,14 +26,9 @@
 from .node import (
     bin,
     hex,
-    nullhex,
-    nullid,
     nullrev,
     sha1nodeconstants,
     short,
-    wdirfilenodeids,
-    wdirhex,
-    wdirid,
     wdirrev,
 )
 from .i18n import _
@@ -232,7 +227,7 @@
 
     @util.propertycache
     def _nodemap(self):
-        nodemap = nodemaputil.NodeMap({nullid: nullrev})
+        nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         for r in range(0, len(self)):
             n = self[r][7]
             nodemap[n] = r
@@ -270,7 +265,7 @@
 
     def __getitem__(self, i):
         if i == -1:
-            return (0, 0, 0, -1, -1, -1, -1, nullid)
+            return (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid)
         return list.__getitem__(self, i)
 
 
@@ -278,7 +273,7 @@
     def parseindex(self, data, inline):
         s = INDEX_ENTRY_V0.size
         index = []
-        nodemap = nodemaputil.NodeMap({nullid: nullrev})
+        nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         n = off = 0
         l = len(data)
         while off + s <= l:
@@ -818,7 +813,10 @@
             raise
         except error.RevlogError:
             # parsers.c radix tree lookup failed
-            if node == wdirid or node in wdirfilenodeids:
+            if (
+                node == self.nodeconstants.wdirid
+                or node in self.nodeconstants.wdirfilenodeids
+            ):
                 raise error.WdirUnsupported
             raise error.LookupError(node, self.indexfile, _(b'no node'))
 
@@ -909,7 +907,7 @@
         i = self.index
         d = i[self.rev(node)]
         # inline node() to avoid function call overhead
-        if d[5] == nullid:
+        if d[5] == self.nullid:
             return i[d[6]][7], i[d[5]][7]
         else:
             return i[d[5]][7], i[d[6]][7]
@@ -1027,7 +1025,7 @@
         not supplied, uses all of the revlog's heads.  If common is not
         supplied, uses nullid."""
         if common is None:
-            common = [nullid]
+            common = [self.nullid]
         if heads is None:
             heads = self.heads()
 
@@ -1133,7 +1131,7 @@
         not supplied, uses all of the revlog's heads.  If common is not
         supplied, uses nullid."""
         if common is None:
-            common = [nullid]
+            common = [self.nullid]
         if heads is None:
             heads = self.heads()
 
@@ -1171,11 +1169,15 @@
                 return nonodes
             lowestrev = min([self.rev(n) for n in roots])
         else:
-            roots = [nullid]  # Everybody's a descendant of nullid
+            roots = [self.nullid]  # Everybody's a descendant of nullid
             lowestrev = nullrev
         if (lowestrev == nullrev) and (heads is None):
             # We want _all_ the nodes!
-            return ([self.node(r) for r in self], [nullid], list(self.heads()))
+            return (
+                [self.node(r) for r in self],
+                [self.nullid],
+                list(self.heads()),
+            )
         if heads is None:
             # All nodes are ancestors, so the latest ancestor is the last
             # node.
@@ -1201,7 +1203,7 @@
                 # grab a node to tag
                 n = nodestotag.pop()
                 # Never tag nullid
-                if n == nullid:
+                if n == self.nullid:
                     continue
                 # A node's revision number represents its place in a
                 # topologically sorted list of nodes.
@@ -1213,7 +1215,7 @@
                         ancestors.add(n)  # Mark as ancestor
                         # Add non-nullid parents to list of nodes to tag.
                         nodestotag.update(
-                            [p for p in self.parents(n) if p != nullid]
+                            [p for p in self.parents(n) if p != self.nullid]
                         )
                     elif n in heads:  # We've seen it before, is it a fake head?
                         # So it is, real heads should not be the ancestors of
@@ -1241,7 +1243,7 @@
                 # We are descending from nullid, and don't need to care about
                 # any other roots.
                 lowestrev = nullrev
-                roots = [nullid]
+                roots = [self.nullid]
         # Transform our roots list into a set.
         descendants = set(roots)
         # Also, keep the original roots so we can filter out roots that aren't
@@ -1335,7 +1337,7 @@
         """
         if start is None and stop is None:
             if not len(self):
-                return [nullid]
+                return [self.nullid]
             return [self.node(r) for r in self.headrevs()]
 
         if start is None:
@@ -1425,7 +1427,7 @@
         if ancs:
             # choose a consistent winner when there's a tie
             return min(map(self.node, ancs))
-        return nullid
+        return self.nullid
 
     def _match(self, id):
         if isinstance(id, int):
@@ -1463,7 +1465,7 @@
 
     def _partialmatch(self, id):
         # we don't care wdirfilenodeids as they should be always full hash
-        maybewdir = wdirhex.startswith(id)
+        maybewdir = self.nodeconstants.wdirhex.startswith(id)
         try:
             partial = self.index.partialmatch(id)
             if partial and self.hasnode(partial):
@@ -1499,8 +1501,8 @@
                 nl = [
                     n for n in nl if hex(n).startswith(id) and self.hasnode(n)
                 ]
-                if nullhex.startswith(id):
-                    nl.append(nullid)
+                if self.nodeconstants.nullhex.startswith(id):
+                    nl.append(self.nullid)
                 if len(nl) > 0:
                     if len(nl) == 1 and not maybewdir:
                         self._pcache[id] = nl[0]
@@ -1560,13 +1562,13 @@
                 length = max(self.index.shortest(node), minlength)
                 return disambiguate(hexnode, length)
             except error.RevlogError:
-                if node != wdirid:
+                if node != self.nodeconstants.wdirid:
                     raise error.LookupError(node, self.indexfile, _(b'no node'))
             except AttributeError:
                 # Fall through to pure code
                 pass
 
-        if node == wdirid:
+        if node == self.nodeconstants.wdirid:
             for length in range(minlength, len(hexnode) + 1):
                 prefix = hexnode[:length]
                 if isvalid(prefix):
@@ -1881,7 +1883,7 @@
             rev = None
 
         # fast path the special `nullid` rev
-        if node == nullid:
+        if node == self.nullid:
             return b"", {}
 
         # ``rawtext`` is the text as stored inside the revlog. Might be the
@@ -2302,11 +2304,14 @@
         - rawtext is optional (can be None); if not set, cachedelta must be set.
           if both are set, they must correspond to each other.
         """
-        if node == nullid:
+        if node == self.nullid:
             raise error.RevlogError(
                 _(b"%s: attempt to add null revision") % self.indexfile
             )
-        if node == wdirid or node in wdirfilenodeids:
+        if (
+            node == self.nodeconstants.wdirid
+            or node in self.nodeconstants.wdirfilenodeids
+        ):
             raise error.RevlogError(
                 _(b"%s: attempt to add wdir revision") % self.indexfile
             )
diff -r 5fa019ceb499 -r d55b71393907 mercurial/scmutil.py
--- a/mercurial/scmutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/scmutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -19,10 +19,8 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
-    wdirid,
     wdirrev,
 )
 from .pycompat import getattr
@@ -450,7 +448,7 @@
     """Return binary node id for a given basectx"""
     node = ctx.node()
     if node is None:
-        return wdirid
+        return ctx.repo().nodeconstants.wdirid
     return node
 
 
@@ -1108,7 +1106,7 @@
                     if roots:
                         newnode = roots[0].node()
                     else:
-                        newnode = nullid
+                        newnode = repo.nullid
                 else:
                     newnode = newnodes[0]
                 moves[oldnode] = newnode
@@ -1506,7 +1504,7 @@
     oldctx = repo[b'.']
     ds = repo.dirstate
     copies = dict(ds.copies())
-    ds.setparents(newctx.node(), nullid)
+    ds.setparents(newctx.node(), repo.nullid)
     s = newctx.status(oldctx, match=match)
     for f in s.modified:
         if ds[f] == b'r':
diff -r 5fa019ceb499 -r d55b71393907 mercurial/setdiscovery.py
--- a/mercurial/setdiscovery.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/setdiscovery.py	Mon Mar 29 01:52:06 2021 +0200
@@ -46,10 +46,7 @@
 import random
 
 from .i18n import _
-from .node import (
-    nullid,
-    nullrev,
-)
+from .node import nullrev
 from . import (
     error,
     policy,
@@ -391,9 +388,9 @@
             audit[b'total-roundtrips'] = 1
 
         if cl.tiprev() == nullrev:
-            if srvheadhashes != [nullid]:
-                return [nullid], True, srvheadhashes
-            return [nullid], False, []
+            if srvheadhashes != [cl.nullid]:
+                return [cl.nullid], True, srvheadhashes
+            return [cl.nullid], False, []
     else:
         # we still need the remote head for the function return
         with remote.commandexecutor() as e:
@@ -406,7 +403,7 @@
 
     knownsrvheads = []  # revnos of remote heads that are known locally
     for node in srvheadhashes:
-        if node == nullid:
+        if node == cl.nullid:
             continue
 
         try:
@@ -503,17 +500,17 @@
     if audit is not None:
         audit[b'total-roundtrips'] = roundtrips
 
-    if not result and srvheadhashes != [nullid]:
+    if not result and srvheadhashes != [cl.nullid]:
         if abortwhenunrelated:
             raise error.Abort(_(b"repository is unrelated"))
         else:
             ui.warn(_(b"warning: repository is unrelated\n"))
         return (
-            {nullid},
+            {cl.nullid},
             True,
             srvheadhashes,
         )
 
-    anyincoming = srvheadhashes != [nullid]
+    anyincoming = srvheadhashes != [cl.nullid]
     result = {clnode(r) for r in result}
     return result, anyincoming, srvheadhashes
diff -r 5fa019ceb499 -r d55b71393907 mercurial/shelve.py
--- a/mercurial/shelve.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/shelve.py	Mon Mar 29 01:52:06 2021 +0200
@@ -31,7 +31,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from . import (
@@ -822,7 +821,7 @@
         pendingctx = state.pendingctx
 
         with repo.dirstate.parentchange():
-            repo.setparents(state.pendingctx.node(), nullid)
+            repo.setparents(state.pendingctx.node(), repo.nullid)
             repo.dirstate.write(repo.currenttransaction())
 
         targetphase = phases.internal
@@ -831,7 +830,7 @@
         overrides = {(b'phases', b'new-commit'): targetphase}
         with repo.ui.configoverride(overrides, b'unshelve'):
             with repo.dirstate.parentchange():
-                repo.setparents(state.parents[0], nullid)
+                repo.setparents(state.parents[0], repo.nullid)
                 newnode, ispartialunshelve = _createunshelvectx(
                     ui, repo, shelvectx, basename, interactive, opts
                 )
@@ -1027,7 +1026,7 @@
             raise error.ConflictResolutionRequired(b'unshelve')
 
         with repo.dirstate.parentchange():
-            repo.setparents(tmpwctx.node(), nullid)
+            repo.setparents(tmpwctx.node(), repo.nullid)
             newnode, ispartialunshelve = _createunshelvectx(
                 ui, repo, shelvectx, basename, interactive, opts
             )
diff -r 5fa019ceb499 -r d55b71393907 mercurial/sparse.py
--- a/mercurial/sparse.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/sparse.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,10 +10,7 @@
 import os
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
+from .node import hex
 from . import (
     error,
     match as matchmod,
@@ -177,7 +174,7 @@
     revs = [
         repo.changelog.rev(node)
         for node in repo.dirstate.parents()
-        if node != nullid
+        if node != repo.nullid
     ]
 
     allincludes = set()
@@ -321,7 +318,7 @@
         revs = [
             repo.changelog.rev(node)
             for node in repo.dirstate.parents()
-            if node != nullid
+            if node != repo.nullid
         ]
 
     signature = configsignature(repo, includetemp=includetemp)
diff -r 5fa019ceb499 -r d55b71393907 mercurial/strip.py
--- a/mercurial/strip.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/strip.py	Mon Mar 29 01:52:06 2021 +0200
@@ -2,7 +2,6 @@
 
 from .i18n import _
 from .pycompat import getattr
-from .node import nullid
 from . import (
     bookmarks as bookmarksmod,
     cmdutil,
@@ -39,7 +38,7 @@
 
     if (
         util.safehasattr(repo, b'mq')
-        and p2 != nullid
+        and p2 != repo.nullid
         and p2 in [x.node for x in repo.mq.applied]
     ):
         unode = p2
@@ -218,7 +217,7 @@
         # if one of the wdir parent is stripped we'll need
         # to update away to an earlier revision
         update = any(
-            p != nullid and cl.rev(p) in strippedrevs
+            p != repo.nullid and cl.rev(p) in strippedrevs
             for p in repo.dirstate.parents()
         )
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/subrepo.py
--- a/mercurial/subrepo.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/subrepo.py	Mon Mar 29 01:52:06 2021 +0200
@@ -21,7 +21,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     short,
 )
 from . import (
@@ -686,7 +685,7 @@
         # we can't fully delete the repository as it may contain
         # local-only history
         self.ui.note(_(b'removing subrepo %s\n') % subrelpath(self))
-        hg.clean(self._repo, nullid, False)
+        hg.clean(self._repo, self._repo.nullid, False)
 
     def _get(self, state):
         source, revision, kind = state
diff -r 5fa019ceb499 -r d55b71393907 mercurial/tagmerge.py
--- a/mercurial/tagmerge.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/tagmerge.py	Mon Mar 29 01:52:06 2021 +0200
@@ -74,9 +74,6 @@
 from __future__ import absolute_import
 
 from .i18n import _
-from .node import (
-    nullhex,
-)
 from . import (
     tags as tagsmod,
     util,
@@ -243,8 +240,8 @@
         pnlosttagset = basetagset - pntagset
         for t in pnlosttagset:
             pntags[t] = basetags[t]
-            if pntags[t][-1][0] != nullhex:
-                pntags[t].append([nullhex, None])
+            if pntags[t][-1][0] != repo.nodeconstants.nullhex:
+                pntags[t].append([repo.nodeconstants.nullhex, None])
 
     conflictedtags = []  # for reporting purposes
     mergedtags = util.sortdict(p1tags)
diff -r 5fa019ceb499 -r d55b71393907 mercurial/tags.py
--- a/mercurial/tags.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/tags.py	Mon Mar 29 01:52:06 2021 +0200
@@ -18,7 +18,6 @@
 from .node import (
     bin,
     hex,
-    nullid,
     nullrev,
     short,
 )
@@ -96,12 +95,12 @@
     return fnodes
 
 
-def _nulltonone(value):
+def _nulltonone(repo, value):
     """convert nullid to None
 
     For tag value, nullid means "deleted". This small utility function helps
     translating that to None."""
-    if value == nullid:
+    if value == repo.nullid:
         return None
     return value
 
@@ -123,14 +122,14 @@
     # list of (tag, old, new): None means missing
     entries = []
     for tag, (new, __) in newtags.items():
-        new = _nulltonone(new)
+        new = _nulltonone(repo, new)
         old, __ = oldtags.pop(tag, (None, None))
-        old = _nulltonone(old)
+        old = _nulltonone(repo, old)
         if old != new:
             entries.append((tag, old, new))
     # handle deleted tags
     for tag, (old, __) in oldtags.items():
-        old = _nulltonone(old)
+        old = _nulltonone(repo, old)
         if old is not None:
             entries.append((tag, old, None))
     entries.sort()
@@ -452,7 +451,7 @@
     repoheads = repo.heads()
     # Case 2 (uncommon): empty repo; get out quickly and don't bother
     # writing an empty cache.
-    if repoheads == [nullid]:
+    if repoheads == [repo.nullid]:
         return ([], {}, valid, {}, False)
 
     # Case 3 (uncommon): cache file missing or empty.
@@ -499,7 +498,7 @@
     for node in nodes:
         fnode = fnodescache.getfnode(node)
         flog = repo.file(b'.hgtags')
-        if fnode != nullid:
+        if fnode != repo.nullid:
             if fnode not in validated_fnodes:
                 if flog.hasnode(fnode):
                     validated_fnodes.add(fnode)
@@ -510,7 +509,7 @@
     if unknown_entries:
         fixed_nodemap = fnodescache.refresh_invalid_nodes(unknown_entries)
         for node, fnode in pycompat.iteritems(fixed_nodemap):
-            if fnode != nullid:
+            if fnode != repo.nullid:
                 cachefnode[node] = fnode
 
     fnodescache.write()
@@ -632,7 +631,7 @@
                 m = name
 
             if repo._tagscache.tagtypes and name in repo._tagscache.tagtypes:
-                old = repo.tags().get(name, nullid)
+                old = repo.tags().get(name, repo.nullid)
                 fp.write(b'%s %s\n' % (hex(old), m))
             fp.write(b'%s %s\n' % (hex(node), m))
         fp.close()
@@ -762,8 +761,8 @@
         If an .hgtags does not exist at the specified revision, nullid is
         returned.
         """
-        if node == nullid:
-            return nullid
+        if node == self._repo.nullid:
+            return node
 
         ctx = self._repo[node]
         rev = ctx.rev()
@@ -826,7 +825,7 @@
                 fnode = ctx.filenode(b'.hgtags')
             except error.LookupError:
                 # No .hgtags file on this revision.
-                fnode = nullid
+                fnode = self._repo.nullid
         return fnode
 
     def setfnode(self, node, fnode):
diff -r 5fa019ceb499 -r d55b71393907 mercurial/templatefuncs.py
--- a/mercurial/templatefuncs.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/templatefuncs.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,10 +10,7 @@
 import re
 
 from .i18n import _
-from .node import (
-    bin,
-    wdirid,
-)
+from .node import bin
 from . import (
     color,
     dagop,
@@ -778,7 +775,7 @@
         try:
             node = scmutil.resolvehexnodeidprefix(repo, hexnode)
         except error.WdirUnsupported:
-            node = wdirid
+            node = repo.nodeconstants.wdirid
         except error.LookupError:
             return hexnode
         if not node:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/templatekw.py
--- a/mercurial/templatekw.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/templatekw.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,8 +10,6 @@
 from .i18n import _
 from .node import (
     hex,
-    nullid,
-    wdirid,
     wdirrev,
 )
 
@@ -412,7 +410,7 @@
 
 def getgraphnodecurrent(repo, ctx, cache):
     wpnodes = repo.dirstate.parents()
-    if wpnodes[1] == nullid:
+    if wpnodes[1] == repo.nullid:
         wpnodes = wpnodes[:1]
     if ctx.node() in wpnodes:
         return b'@'
@@ -525,11 +523,12 @@
     ctx = context.resource(mapping, b'ctx')
     mnode = ctx.manifestnode()
     if mnode is None:
-        mnode = wdirid
+        mnode = repo.nodeconstants.wdirid
         mrev = wdirrev
+        mhex = repo.nodeconstants.wdirhex
     else:
         mrev = repo.manifestlog.rev(mnode)
-    mhex = hex(mnode)
+        mhex = hex(mnode)
     mapping = context.overlaymap(mapping, {b'rev': mrev, b'node': mhex})
     f = context.process(b'manifest', mapping)
     return templateutil.hybriditem(
diff -r 5fa019ceb499 -r d55b71393907 mercurial/testing/storage.py
--- a/mercurial/testing/storage.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/testing/storage.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,7 +11,6 @@
 
 from ..node import (
     hex,
-    nullid,
     nullrev,
 )
 from ..pycompat import getattr
@@ -51,7 +50,7 @@
         self.assertFalse(f.hasnode(None))
         self.assertFalse(f.hasnode(0))
         self.assertFalse(f.hasnode(nullrev))
-        self.assertFalse(f.hasnode(nullid))
+        self.assertFalse(f.hasnode(f.nullid))
         self.assertFalse(f.hasnode(b'0'))
         self.assertFalse(f.hasnode(b'a' * 20))
 
@@ -64,8 +63,8 @@
 
         self.assertEqual(list(f.revs(start=20)), [])
 
-        # parents() and parentrevs() work with nullid/nullrev.
-        self.assertEqual(f.parents(nullid), (nullid, nullid))
+        # parents() and parentrevs() work with f.nullid/nullrev.
+        self.assertEqual(f.parents(f.nullid), (f.nullid, f.nullid))
         self.assertEqual(f.parentrevs(nullrev), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
@@ -78,9 +77,9 @@
             with self.assertRaises(IndexError):
                 f.parentrevs(i)
 
-        # nullid/nullrev lookup always works.
-        self.assertEqual(f.rev(nullid), nullrev)
-        self.assertEqual(f.node(nullrev), nullid)
+        # f.nullid/nullrev lookup always works.
+        self.assertEqual(f.rev(f.nullid), nullrev)
+        self.assertEqual(f.node(nullrev), f.nullid)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
@@ -92,16 +91,16 @@
             with self.assertRaises(IndexError):
                 f.node(i)
 
-        self.assertEqual(f.lookup(nullid), nullid)
-        self.assertEqual(f.lookup(nullrev), nullid)
-        self.assertEqual(f.lookup(hex(nullid)), nullid)
-        self.assertEqual(f.lookup(b'%d' % nullrev), nullid)
+        self.assertEqual(f.lookup(f.nullid), f.nullid)
+        self.assertEqual(f.lookup(nullrev), f.nullid)
+        self.assertEqual(f.lookup(hex(f.nullid)), f.nullid)
+        self.assertEqual(f.lookup(b'%d' % nullrev), f.nullid)
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'badvalue')
 
         with self.assertRaises(error.LookupError):
-            f.lookup(hex(nullid)[0:12])
+            f.lookup(hex(f.nullid)[0:12])
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'-2')
@@ -140,19 +139,19 @@
             with self.assertRaises(IndexError):
                 f.iscensored(i)
 
-        self.assertEqual(list(f.commonancestorsheads(nullid, nullid)), [])
+        self.assertEqual(list(f.commonancestorsheads(f.nullid, f.nullid)), [])
 
         with self.assertRaises(ValueError):
             self.assertEqual(list(f.descendants([])), [])
 
         self.assertEqual(list(f.descendants([nullrev])), [])
 
-        self.assertEqual(f.heads(), [nullid])
-        self.assertEqual(f.heads(nullid), [nullid])
-        self.assertEqual(f.heads(None, [nullid]), [nullid])
-        self.assertEqual(f.heads(nullid, [nullid]), [nullid])
+        self.assertEqual(f.heads(), [f.nullid])
+        self.assertEqual(f.heads(f.nullid), [f.nullid])
+        self.assertEqual(f.heads(None, [f.nullid]), [f.nullid])
+        self.assertEqual(f.heads(f.nullid, [f.nullid]), [f.nullid])
 
-        self.assertEqual(f.children(nullid), [])
+        self.assertEqual(f.children(f.nullid), [])
 
         with self.assertRaises(error.LookupError):
             f.children(b'\x01' * 20)
@@ -160,7 +159,7 @@
     def testsinglerevision(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node = f.add(b'initial', None, tr, 0, nullid, nullid)
+            node = f.add(b'initial', None, tr, 0, f.nullid, f.nullid)
 
         self.assertEqual(len(f), 1)
         self.assertEqual(list(f), [0])
@@ -174,7 +173,7 @@
         self.assertTrue(f.hasnode(node))
         self.assertFalse(f.hasnode(hex(node)))
         self.assertFalse(f.hasnode(nullrev))
-        self.assertFalse(f.hasnode(nullid))
+        self.assertFalse(f.hasnode(f.nullid))
         self.assertFalse(f.hasnode(node[0:12]))
         self.assertFalse(f.hasnode(hex(node)[0:20]))
 
@@ -188,7 +187,7 @@
         self.assertEqual(list(f.revs(1, 0)), [1, 0])
         self.assertEqual(list(f.revs(2, 0)), [2, 1, 0])
 
-        self.assertEqual(f.parents(node), (nullid, nullid))
+        self.assertEqual(f.parents(node), (f.nullid, f.nullid))
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
@@ -209,7 +208,7 @@
 
         self.assertEqual(f.lookup(node), node)
         self.assertEqual(f.lookup(0), node)
-        self.assertEqual(f.lookup(-1), nullid)
+        self.assertEqual(f.lookup(-1), f.nullid)
         self.assertEqual(f.lookup(b'0'), node)
         self.assertEqual(f.lookup(hex(node)), node)
 
@@ -256,9 +255,9 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
-            node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, None, tr, 1, node0, f.nullid)
+            node2 = f.add(fulltext2, None, tr, 3, node1, f.nullid)
 
         self.assertEqual(len(f), 3)
         self.assertEqual(list(f), [0, 1, 2])
@@ -284,9 +283,9 @@
         # TODO this is wrong
         self.assertEqual(list(f.revs(3, 2)), [3, 2])
 
-        self.assertEqual(f.parents(node0), (nullid, nullid))
-        self.assertEqual(f.parents(node1), (node0, nullid))
-        self.assertEqual(f.parents(node2), (node1, nullid))
+        self.assertEqual(f.parents(node0), (f.nullid, f.nullid))
+        self.assertEqual(f.parents(node1), (node0, f.nullid))
+        self.assertEqual(f.parents(node2), (node1, f.nullid))
 
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
         self.assertEqual(f.parentrevs(1), (0, nullrev))
@@ -330,7 +329,7 @@
         with self.assertRaises(IndexError):
             f.iscensored(3)
 
-        self.assertEqual(f.commonancestorsheads(node1, nullid), [])
+        self.assertEqual(f.commonancestorsheads(node1, f.nullid), [])
         self.assertEqual(f.commonancestorsheads(node1, node0), [node0])
         self.assertEqual(f.commonancestorsheads(node1, node1), [node1])
         self.assertEqual(f.commonancestorsheads(node0, node1), [node0])
@@ -364,12 +363,12 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'1', None, tr, 1, node0, nullid)
-            node2 = f.add(b'2', None, tr, 2, node1, nullid)
-            node3 = f.add(b'3', None, tr, 3, node0, nullid)
-            node4 = f.add(b'4', None, tr, 4, node3, nullid)
-            node5 = f.add(b'5', None, tr, 5, node0, nullid)
+            node0 = f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'1', None, tr, 1, node0, f.nullid)
+            node2 = f.add(b'2', None, tr, 2, node1, f.nullid)
+            node3 = f.add(b'3', None, tr, 3, node0, f.nullid)
+            node4 = f.add(b'4', None, tr, 4, node3, f.nullid)
+            node5 = f.add(b'5', None, tr, 5, node0, f.nullid)
 
         self.assertEqual(len(f), 6)
 
@@ -427,24 +426,24 @@
             with self.assertRaises(IndexError):
                 f.size(i)
 
-        self.assertEqual(f.revision(nullid), b'')
-        self.assertEqual(f.rawdata(nullid), b'')
+        self.assertEqual(f.revision(f.nullid), b'')
+        self.assertEqual(f.rawdata(f.nullid), b'')
 
         with self.assertRaises(error.LookupError):
             f.revision(b'\x01' * 20)
 
-        self.assertEqual(f.read(nullid), b'')
+        self.assertEqual(f.read(f.nullid), b'')
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
-        self.assertFalse(f.renamed(nullid))
+        self.assertFalse(f.renamed(f.nullid))
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
-        self.assertTrue(f.cmp(nullid, b''))
-        self.assertTrue(f.cmp(nullid, b'foo'))
+        self.assertTrue(f.cmp(f.nullid, b''))
+        self.assertTrue(f.cmp(f.nullid, b'foo'))
 
         with self.assertRaises(error.LookupError):
             f.cmp(b'\x01' * 20, b'irrelevant')
@@ -455,7 +454,7 @@
             next(gen)
 
         # Emitting null node yields nothing.
-        gen = f.emitrevisions([nullid])
+        gen = f.emitrevisions([f.nullid])
         with self.assertRaises(StopIteration):
             next(gen)
 
@@ -468,7 +467,7 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node = f.add(fulltext, None, tr, 0, nullid, nullid)
+            node = f.add(fulltext, None, tr, 0, f.nullid, f.nullid)
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(
@@ -496,10 +495,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertIsNone(rev.delta)
@@ -512,10 +511,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext)
         self.assertIsNone(rev.delta)
@@ -534,9 +533,9 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
-            node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, None, tr, 1, node0, f.nullid)
+            node2 = f.add(fulltext2, None, tr, 3, node1, f.nullid)
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(
@@ -596,10 +595,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext0)
         self.assertIsNone(rev.delta)
@@ -608,7 +607,7 @@
 
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
@@ -622,7 +621,7 @@
 
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
@@ -641,10 +640,10 @@
         rev = next(gen)
 
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext0)
         self.assertIsNone(rev.delta)
@@ -653,7 +652,7 @@
 
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
@@ -667,7 +666,7 @@
 
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
@@ -700,16 +699,16 @@
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext2)
         self.assertIsNone(rev.delta)
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         # Delta behavior is storage dependent, so we can't easily test it.
 
         with self.assertRaises(StopIteration):
@@ -722,8 +721,8 @@
         rev = next(gen)
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext1)
         self.assertIsNone(rev.delta)
@@ -731,7 +730,7 @@
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
@@ -751,7 +750,7 @@
         rev = next(gen)
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
@@ -768,9 +767,9 @@
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(
@@ -789,9 +788,9 @@
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
-        self.assertEqual(rev.p1node, nullid)
-        self.assertEqual(rev.p2node, nullid)
-        self.assertEqual(rev.basenode, nullid)
+        self.assertEqual(rev.p1node, f.nullid)
+        self.assertEqual(rev.p2node, f.nullid)
+        self.assertEqual(rev.basenode, f.nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(
@@ -802,7 +801,7 @@
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
-        self.assertEqual(rev.p2node, nullid)
+        self.assertEqual(rev.p2node, f.nullid)
         self.assertEqual(rev.basenode, node0)
 
         with self.assertRaises(StopIteration):
@@ -841,11 +840,11 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, meta1, tr, 1, node0, nullid)
-            node2 = f.add(fulltext2, meta2, tr, 2, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, meta1, tr, 1, node0, f.nullid)
+            node2 = f.add(fulltext2, meta2, tr, 2, f.nullid, f.nullid)
 
-        # Metadata header isn't recognized when parent isn't nullid.
+        # Metadata header isn't recognized when parent isn't f.nullid.
         self.assertEqual(f.size(1), len(stored1))
         self.assertEqual(f.size(2), len(fulltext2))
 
@@ -886,8 +885,8 @@
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, {}, tr, 0, nullid, nullid)
-            node1 = f.add(fulltext1, meta1, tr, 1, nullid, nullid)
+            node0 = f.add(fulltext0, {}, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(fulltext1, meta1, tr, 1, f.nullid, f.nullid)
 
         # TODO this is buggy.
         self.assertEqual(f.size(0), len(fulltext0) + 4)
@@ -916,15 +915,15 @@
         fulltext1 = fulltext0 + b'bar\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         self.assertEqual(len(f), 2)
-        self.assertEqual(f.parents(node1), (node0, nullid))
+        self.assertEqual(f.parents(node1), (node0, f.nullid))
 
         # revision() raises since it performs hash verification.
         with self.assertRaises(error.StorageError):
@@ -951,11 +950,11 @@
         fulltext1 = fulltext0 + b'bar\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         with self.assertRaises(error.StorageError):
@@ -973,11 +972,11 @@
         fulltext1 = fulltext0 + b'bar\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         with self.assertRaises(error.StorageError):
@@ -994,22 +993,22 @@
         fulltext2 = fulltext1 + b'baz\n'
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
             node1 = b'\xaa' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, rawtext=fulltext1
+                f, tr, node1, node0, f.nullid, 1, rawtext=fulltext1
             )
 
         with self.assertRaises(error.StorageError):
             f.read(node1)
 
-        node2 = storageutil.hashrevisionsha1(fulltext2, node1, nullid)
+        node2 = storageutil.hashrevisionsha1(fulltext2, node1, f.nullid)
 
         with self._maketransactionfn() as tr:
             delta = mdiff.textdiff(fulltext1, fulltext2)
             self._addrawrevisionfn(
-                f, tr, node2, node1, nullid, 2, delta=(1, delta)
+                f, tr, node2, node1, f.nullid, 2, delta=(1, delta)
             )
 
         self.assertEqual(len(f), 3)
@@ -1029,13 +1028,13 @@
         )
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
 
             # The node value doesn't matter since we can't verify it.
             node1 = b'\xbb' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, stored1, censored=True
+                f, tr, node1, node0, f.nullid, 1, stored1, censored=True
             )
 
         self.assertTrue(f.iscensored(1))
@@ -1063,13 +1062,13 @@
         )
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
 
             # The node value doesn't matter since we can't verify it.
             node1 = b'\xbb' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, stored1, censored=True
+                f, tr, node1, node0, f.nullid, 1, stored1, censored=True
             )
 
         with self.assertRaises(error.CensoredNodeError):
@@ -1088,10 +1087,10 @@
     def testaddnoop(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'foo', None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'foo', None, tr, 0, f.nullid, f.nullid)
             # Varying by linkrev shouldn't impact hash.
-            node2 = f.add(b'foo', None, tr, 1, nullid, nullid)
+            node2 = f.add(b'foo', None, tr, 1, f.nullid, f.nullid)
 
         self.assertEqual(node1, node0)
         self.assertEqual(node2, node0)
@@ -1102,7 +1101,9 @@
         with self._maketransactionfn() as tr:
             # Adding a revision with bad node value fails.
             with self.assertRaises(error.StorageError):
-                f.addrevision(b'foo', tr, 0, nullid, nullid, node=b'\x01' * 20)
+                f.addrevision(
+                    b'foo', tr, 0, f.nullid, f.nullid, node=b'\x01' * 20
+                )
 
     def testaddrevisionunknownflag(self):
         f = self._makefilefn()
@@ -1113,7 +1114,7 @@
                     break
 
             with self.assertRaises(error.StorageError):
-                f.addrevision(b'foo', tr, 0, nullid, nullid, flags=flags)
+                f.addrevision(b'foo', tr, 0, f.nullid, f.nullid, flags=flags)
 
     def testaddgroupsimple(self):
         f = self._makefilefn()
@@ -1153,12 +1154,12 @@
         delta0 = mdiff.trivialdiffheader(len(fulltext0)) + fulltext0
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
+            node0 = f.add(fulltext0, None, tr, 0, f.nullid, f.nullid)
 
         f = self._makefilefn()
 
         deltas = [
-            (node0, nullid, nullid, nullid, nullid, delta0, 0, {}),
+            (node0, f.nullid, f.nullid, f.nullid, f.nullid, delta0, 0, {}),
         ]
 
         with self._maketransactionfn() as tr:
@@ -1207,7 +1208,7 @@
         nodes = []
         with self._maketransactionfn() as tr:
             for fulltext in fulltexts:
-                nodes.append(f.add(fulltext, None, tr, 0, nullid, nullid))
+                nodes.append(f.add(fulltext, None, tr, 0, f.nullid, f.nullid))
 
         f = self._makefilefn()
         deltas = []
@@ -1215,7 +1216,7 @@
             delta = mdiff.trivialdiffheader(len(fulltext)) + fulltext
 
             deltas.append(
-                (nodes[i], nullid, nullid, nullid, nullid, delta, 0, {})
+                (nodes[i], f.nullid, f.nullid, f.nullid, f.nullid, delta, 0, {})
             )
 
         with self._maketransactionfn() as tr:
@@ -1254,18 +1255,18 @@
         )
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo\n' * 30, None, tr, 0, nullid, nullid)
+            node0 = f.add(b'foo\n' * 30, None, tr, 0, f.nullid, f.nullid)
 
             # The node value doesn't matter since we can't verify it.
             node1 = b'\xbb' * 20
 
             self._addrawrevisionfn(
-                f, tr, node1, node0, nullid, 1, stored1, censored=True
+                f, tr, node1, node0, f.nullid, 1, stored1, censored=True
             )
 
         delta = mdiff.textdiff(b'bar\n' * 30, (b'bar\n' * 30) + b'baz\n')
         deltas = [
-            (b'\xcc' * 20, node1, nullid, b'\x01' * 20, node1, delta, 0, {})
+            (b'\xcc' * 20, node1, f.nullid, b'\x01' * 20, node1, delta, 0, {})
         ]
 
         with self._maketransactionfn() as tr:
@@ -1276,9 +1277,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'foo\n' * 30, None, tr, 0, nullid, nullid)
-            node1 = f.add(b'foo\n' * 31, None, tr, 1, node0, nullid)
-            node2 = f.add(b'foo\n' * 32, None, tr, 2, node1, nullid)
+            node0 = f.add(b'foo\n' * 30, None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'foo\n' * 31, None, tr, 1, node0, f.nullid)
+            node2 = f.add(b'foo\n' * 32, None, tr, 2, node1, f.nullid)
 
         with self._maketransactionfn() as tr:
             f.censorrevision(tr, node1)
@@ -1298,7 +1299,7 @@
 
         with self._maketransactionfn() as tr:
             for rev in range(10):
-                f.add(b'%d' % rev, None, tr, rev, nullid, nullid)
+                f.add(b'%d' % rev, None, tr, rev, f.nullid, f.nullid)
 
         for rev in range(10):
             self.assertEqual(f.getstrippoint(rev), (rev, set()))
@@ -1308,10 +1309,10 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            p1 = nullid
+            p1 = f.nullid
 
             for rev in range(10):
-                f.add(b'%d' % rev, None, tr, rev, p1, nullid)
+                f.add(b'%d' % rev, None, tr, rev, p1, f.nullid)
 
         for rev in range(10):
             self.assertEqual(f.getstrippoint(rev), (rev, set()))
@@ -1320,11 +1321,11 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'1', None, tr, 1, node0, nullid)
-            f.add(b'2', None, tr, 2, node1, nullid)
-            f.add(b'3', None, tr, 3, node0, nullid)
-            f.add(b'4', None, tr, 4, node0, nullid)
+            node0 = f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'1', None, tr, 1, node0, f.nullid)
+            f.add(b'2', None, tr, 2, node1, f.nullid)
+            f.add(b'3', None, tr, 3, node0, f.nullid)
+            f.add(b'4', None, tr, 4, node0, f.nullid)
 
         for rev in range(5):
             self.assertEqual(f.getstrippoint(rev), (rev, set()))
@@ -1333,9 +1334,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
-            f.add(b'1', None, tr, 10, node0, nullid)
-            f.add(b'2', None, tr, 5, node0, nullid)
+            node0 = f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            f.add(b'1', None, tr, 10, node0, f.nullid)
+            f.add(b'2', None, tr, 5, node0, f.nullid)
 
         self.assertEqual(f.getstrippoint(0), (0, set()))
         self.assertEqual(f.getstrippoint(1), (1, set()))
@@ -1362,9 +1363,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            p1 = nullid
+            p1 = f.nullid
             for rev in range(10):
-                p1 = f.add(b'%d' % rev, None, tr, rev, p1, nullid)
+                p1 = f.add(b'%d' % rev, None, tr, rev, p1, f.nullid)
 
         self.assertEqual(len(f), 10)
 
@@ -1377,9 +1378,9 @@
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
-            f.add(b'0', None, tr, 0, nullid, nullid)
-            node1 = f.add(b'1', None, tr, 5, nullid, nullid)
-            node2 = f.add(b'2', None, tr, 10, nullid, nullid)
+            f.add(b'0', None, tr, 0, f.nullid, f.nullid)
+            node1 = f.add(b'1', None, tr, 5, f.nullid, f.nullid)
+            node2 = f.add(b'2', None, tr, 10, f.nullid, f.nullid)
 
         self.assertEqual(len(f), 3)
 
diff -r 5fa019ceb499 -r d55b71393907 mercurial/treediscovery.py
--- a/mercurial/treediscovery.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/treediscovery.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,10 +10,7 @@
 import collections
 
 from .i18n import _
-from .node import (
-    nullid,
-    short,
-)
+from .node import short
 from . import (
     error,
     pycompat,
@@ -44,11 +41,11 @@
     if audit is not None:
         audit[b'total-roundtrips'] = 1
 
-    if repo.changelog.tip() == nullid:
-        base.add(nullid)
-        if heads != [nullid]:
-            return [nullid], [nullid], list(heads)
-        return [nullid], [], heads
+    if repo.changelog.tip() == repo.nullid:
+        base.add(repo.nullid)
+        if heads != [repo.nullid]:
+            return [repo.nullid], [repo.nullid], list(heads)
+        return [repo.nullid], [], heads
 
     # assume we're closer to the tip than the root
     # and start by examining the heads
@@ -84,7 +81,7 @@
                 continue
 
             repo.ui.debug(b"examining %s:%s\n" % (short(n[0]), short(n[1])))
-            if n[0] == nullid:  # found the end of the branch
+            if n[0] == repo.nullid:  # found the end of the branch
                 pass
             elif n in seenbranch:
                 repo.ui.debug(b"branch already found\n")
@@ -170,7 +167,7 @@
             raise error.RepoError(_(b"already have changeset ") + short(f[:4]))
 
     base = list(base)
-    if base == [nullid]:
+    if base == [repo.nullid]:
         if force:
             repo.ui.warn(_(b"warning: repository is unrelated\n"))
         else:
diff -r 5fa019ceb499 -r d55b71393907 mercurial/util.py
--- a/mercurial/util.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/util.py	Mon Mar 29 01:52:06 2021 +0200
@@ -34,6 +34,7 @@
 import traceback
 import warnings
 
+from .node import hex
 from .thirdparty import attr
 from .pycompat import (
     delattr,
diff -r 5fa019ceb499 -r d55b71393907 mercurial/utils/storageutil.py
--- a/mercurial/utils/storageutil.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/utils/storageutil.py	Mon Mar 29 01:52:06 2021 +0200
@@ -13,8 +13,8 @@
 from ..i18n import _
 from ..node import (
     bin,
-    nullid,
     nullrev,
+    sha1nodeconstants,
 )
 from .. import (
     dagop,
@@ -26,7 +26,7 @@
 from ..revlogutils import sidedata as sidedatamod
 from ..utils import hashutil
 
-_nullhash = hashutil.sha1(nullid)
+_nullhash = hashutil.sha1(sha1nodeconstants.nullid)
 
 
 def hashrevisionsha1(text, p1, p2):
@@ -37,7 +37,7 @@
     content in the revision graph.
     """
     # As of now, if one of the parent node is null, p2 is null
-    if p2 == nullid:
+    if p2 == sha1nodeconstants.nullid:
         # deep copy of a hash is faster than creating one
         s = _nullhash.copy()
         s.update(p1)
@@ -107,7 +107,7 @@
     Returns ``False`` if the file has no copy metadata. Otherwise a
     2-tuple of the source filename and node.
     """
-    if store.parents(node)[0] != nullid:
+    if store.parents(node)[0] != sha1nodeconstants.nullid:
         return False
 
     meta = parsemeta(store.revision(node))[0]
diff -r 5fa019ceb499 -r d55b71393907 mercurial/verify.py
--- a/mercurial/verify.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/verify.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,13 +10,8 @@
 import os
 
 from .i18n import _
-from .node import (
-    nullid,
-    short,
-)
-from .utils import (
-    stringutil,
-)
+from .node import short
+from .utils import stringutil
 
 from . import (
     error,
@@ -159,13 +154,13 @@
 
         try:
             p1, p2 = obj.parents(node)
-            if p1 not in seen and p1 != nullid:
+            if p1 not in seen and p1 != self.repo.nullid:
                 self._err(
                     lr,
                     _(b"unknown parent 1 %s of %s") % (short(p1), short(node)),
                     f,
                 )
-            if p2 not in seen and p2 != nullid:
+            if p2 not in seen and p2 != self.repo.nullid:
                 self._err(
                     lr,
                     _(b"unknown parent 2 %s of %s") % (short(p2), short(node)),
@@ -267,7 +262,7 @@
 
             try:
                 changes = cl.read(n)
-                if changes[0] != nullid:
+                if changes[0] != self.repo.nullid:
                     mflinkrevs.setdefault(changes[0], []).append(i)
                     self.refersmf = True
                 for f in changes[3]:
@@ -598,7 +593,7 @@
                                 % (rp[0], short(rp[1])),
                                 f,
                             )
-                        elif rp[1] == nullid:
+                        elif rp[1] == self.repo.nullid:
                             ui.note(
                                 _(
                                     b"warning: %s@%s: copy source"
diff -r 5fa019ceb499 -r d55b71393907 mercurial/wireprotov1server.py
--- a/mercurial/wireprotov1server.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/wireprotov1server.py	Mon Mar 29 01:52:06 2021 +0200
@@ -11,10 +11,7 @@
 import os
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
+from .node import hex
 from .pycompat import getattr
 
 from . import (
@@ -470,7 +467,7 @@
         clheads = set(repo.changelog.heads())
         heads = set(opts.get(b'heads', set()))
         common = set(opts.get(b'common', set()))
-        common.discard(nullid)
+        common.discard(repo.nullid)
         if (
             repo.ui.configbool(b'server', b'pullbundle')
             and b'partial-pull' in proto.getprotocaps()
diff -r 5fa019ceb499 -r d55b71393907 mercurial/wireprotov2server.py
--- a/mercurial/wireprotov2server.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/mercurial/wireprotov2server.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,10 +10,7 @@
 import contextlib
 
 from .i18n import _
-from .node import (
-    hex,
-    nullid,
-)
+from .node import hex
 from . import (
     discovery,
     encoding,
@@ -950,7 +947,7 @@
             if spec[b'roots']:
                 common = [n for n in spec[b'roots'] if clhasnode(n)]
             else:
-                common = [nullid]
+                common = [repo.nullid]
 
             for n in discovery.outgoing(repo, common, spec[b'heads']).missing:
                 if n not in seen:
diff -r 5fa019ceb499 -r d55b71393907 tests/drawdag.py
--- a/tests/drawdag.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/drawdag.py	Mon Mar 29 01:52:06 2021 +0200
@@ -86,7 +86,6 @@
 import itertools
 import re
 
-from mercurial.node import nullid
 from mercurial.i18n import _
 from mercurial import (
     context,
@@ -299,7 +298,7 @@
         self._added = added
         self._parents = parentctxs
         while len(self._parents) < 2:
-            self._parents.append(repo[nullid])
+            self._parents.append(repo[repo.nullid])
 
     def filectx(self, key):
         return simplefilectx(key, self._added[key])
@@ -388,7 +387,7 @@
         content = content.replace(br'\n', b'\n').replace(br'\1', b'\1')
         files[name][path] = content
 
-    committed = {None: nullid}  # {name: node}
+    committed = {None: repo.nullid}  # {name: node}
 
     # for leaf nodes, try to find existing nodes in repo
     for name, parents in edges.items():
diff -r 5fa019ceb499 -r d55b71393907 tests/simplestorerepo.py
--- a/tests/simplestorerepo.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/simplestorerepo.py	Mon Mar 29 01:52:06 2021 +0200
@@ -18,7 +18,6 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     nullrev,
 )
 from mercurial.thirdparty import attr
@@ -136,18 +135,18 @@
             self._indexbynode[entry[b'node']] = entry
             self._indexbyrev[i] = entry
 
-        self._indexbynode[nullid] = {
-            b'node': nullid,
-            b'p1': nullid,
-            b'p2': nullid,
+        self._indexbynode[self._repo.nullid] = {
+            b'node': self._repo.nullid,
+            b'p1': self._repo.nullid,
+            b'p2': self._repo.nullid,
             b'linkrev': nullrev,
             b'flags': 0,
         }
 
         self._indexbyrev[nullrev] = {
-            b'node': nullid,
-            b'p1': nullid,
-            b'p2': nullid,
+            b'node': self._repo.nullid,
+            b'p1': self._repo.nullid,
+            b'p2': self._repo.nullid,
             b'linkrev': nullrev,
             b'flags': 0,
         }
@@ -160,7 +159,7 @@
                 (0, 0, 0, -1, entry[b'linkrev'], p1rev, p2rev, entry[b'node'])
             )
 
-        self._index.append((0, 0, 0, -1, -1, -1, -1, nullid))
+        self._index.append((0, 0, 0, -1, -1, -1, -1, self._repo.nullid))
 
     def __len__(self):
         return len(self._indexdata)
@@ -288,7 +287,7 @@
             node = nodeorrev
         validatenode(node)
 
-        if node == nullid:
+        if node == self._repo.nullid:
             return b''
 
         rev = self.rev(node)
@@ -325,7 +324,7 @@
     def renamed(self, node):
         validatenode(node)
 
-        if self.parents(node)[0] != nullid:
+        if self.parents(node)[0] != self._repo.nullid:
             return False
 
         fulltext = self.revision(node)
@@ -451,7 +450,7 @@
         sidedata_helpers=None,
     ):
         # TODO this will probably break on some ordering options.
-        nodes = [n for n in nodes if n != nullid]
+        nodes = [n for n in nodes if n != self._repo.nullid]
         if not nodes:
             return
         for delta in storageutil.emitrevisions(
@@ -559,7 +558,7 @@
                 continue
 
             # Need to resolve the fulltext from the delta base.
-            if deltabase == nullid:
+            if deltabase == self._repo.nullid:
                 text = mdiff.patch(b'', delta)
             else:
                 text = mdiff.patch(self.revision(deltabase), delta)
@@ -588,11 +587,11 @@
         # This is copied from revlog.py.
         if start is None and stop is None:
             if not len(self):
-                return [nullid]
+                return [self._repo.nullid]
             return [self.node(r) for r in self._headrevs()]
 
         if start is None:
-            start = nullid
+            start = self._repo.nullid
         if stop is None:
             stop = []
         stoprevs = {self.rev(n) for n in stop}
diff -r 5fa019ceb499 -r d55b71393907 tests/test-annotate.t
--- a/tests/test-annotate.t	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-annotate.t	Mon Mar 29 01:52:06 2021 +0200
@@ -479,19 +479,19 @@
 
   $ cat > ../legacyrepo.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import commit, error, extensions, node
+  > from mercurial import commit, error, extensions
   > def _filecommit(orig, repo, fctx, manifest1, manifest2,
   >                 linkrev, tr, includecopymeta, ms):
   >     fname = fctx.path()
   >     text = fctx.data()
   >     flog = repo.file(fname)
-  >     fparent1 = manifest1.get(fname, node.nullid)
-  >     fparent2 = manifest2.get(fname, node.nullid)
+  >     fparent1 = manifest1.get(fname, repo.nullid)
+  >     fparent2 = manifest2.get(fname, repo.nullid)
   >     meta = {}
   >     copy = fctx.copysource()
   >     if copy and copy != fname:
   >         raise error.Abort('copying is not supported')
-  >     if fparent2 != node.nullid:
+  >     if fparent2 != repo.nullid:
   >         return flog.add(text, meta, tr, linkrev,
   >                         fparent1, fparent2), 'modified'
   >     raise error.Abort('only merging is supported')
diff -r 5fa019ceb499 -r d55b71393907 tests/test-commit.t
--- a/tests/test-commit.t	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-commit.t	Mon Mar 29 01:52:06 2021 +0200
@@ -646,14 +646,14 @@
 verify pathauditor blocks evil filepaths
   $ cat > evil-commit.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import context, hg, node, ui as uimod
+  > from mercurial import context, hg, ui as uimod
   > notrc = u".h\u200cg".encode('utf-8') + b'/hgrc'
   > u = uimod.ui.load()
   > r = hg.repository(u, b'.')
   > def filectxfn(repo, memctx, path):
   >     return context.memfilectx(repo, memctx, path,
   >         b'[hooks]\nupdate = echo owned')
-  > c = context.memctx(r, [r.changelog.tip(), node.nullid],
+  > c = context.memctx(r, [r.changelog.tip(), r.nullid],
   >                    b'evil', [notrc], filectxfn, 0)
   > r.commitctx(c)
   > EOF
@@ -672,14 +672,14 @@
   repository tip rolled back to revision 2 (undo commit)
   $ cat > evil-commit.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import context, hg, node, ui as uimod
+  > from mercurial import context, hg, ui as uimod
   > notrc = b"HG~1/hgrc"
   > u = uimod.ui.load()
   > r = hg.repository(u, b'.')
   > def filectxfn(repo, memctx, path):
   >     return context.memfilectx(repo, memctx, path,
   >         b'[hooks]\nupdate = echo owned')
-  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
+  > c = context.memctx(r, [r[b'tip'].node(), r.nullid],
   >                    b'evil', [notrc], filectxfn, 0)
   > r.commitctx(c)
   > EOF
@@ -692,14 +692,14 @@
   repository tip rolled back to revision 2 (undo commit)
   $ cat > evil-commit.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import context, hg, node, ui as uimod
+  > from mercurial import context, hg, ui as uimod
   > notrc = b"HG8B6C~2/hgrc"
   > u = uimod.ui.load()
   > r = hg.repository(u, b'.')
   > def filectxfn(repo, memctx, path):
   >     return context.memfilectx(repo, memctx, path,
   >         b'[hooks]\nupdate = echo owned')
-  > c = context.memctx(r, [r[b'tip'].node(), node.nullid],
+  > c = context.memctx(r, [r[b'tip'].node(), r.nullid],
   >                    b'evil', [notrc], filectxfn, 0)
   > r.commitctx(c)
   > EOF
diff -r 5fa019ceb499 -r d55b71393907 tests/test-fastannotate-hg.t
--- a/tests/test-fastannotate-hg.t	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-fastannotate-hg.t	Mon Mar 29 01:52:06 2021 +0200
@@ -482,19 +482,19 @@
 
   $ cat > ../legacyrepo.py <<EOF
   > from __future__ import absolute_import
-  > from mercurial import commit, error, extensions, node
+  > from mercurial import commit, error, extensions
   > def _filecommit(orig, repo, fctx, manifest1, manifest2,
   >                 linkrev, tr, includecopymeta, ms):
   >     fname = fctx.path()
   >     text = fctx.data()
   >     flog = repo.file(fname)
-  >     fparent1 = manifest1.get(fname, node.nullid)
-  >     fparent2 = manifest2.get(fname, node.nullid)
+  >     fparent1 = manifest1.get(fname, repo.nullid)
+  >     fparent2 = manifest2.get(fname, repo.nullid)
   >     meta = {}
   >     copy = fctx.copysource()
   >     if copy and copy != fname:
   >         raise error.Abort('copying is not supported')
-  >     if fparent2 != node.nullid:
+  >     if fparent2 != repo.nullid:
   >         return flog.add(text, meta, tr, linkrev,
   >                         fparent1, fparent2), 'modified'
   >     raise error.Abort('only merging is supported')
diff -r 5fa019ceb499 -r d55b71393907 tests/test-filelog.py
--- a/tests/test-filelog.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-filelog.py	Mon Mar 29 01:52:06 2021 +0200
@@ -4,10 +4,7 @@
 """
 from __future__ import absolute_import, print_function
 
-from mercurial.node import (
-    hex,
-    nullid,
-)
+from mercurial.node import hex
 from mercurial import (
     hg,
     ui as uimod,
@@ -22,7 +19,7 @@
 def addrev(text, renamed=False):
     if renamed:
         # data doesn't matter. Just make sure filelog.renamed() returns True
-        meta = {b'copyrev': hex(nullid), b'copy': b'bar'}
+        meta = {b'copyrev': hex(repo.nullid), b'copy': b'bar'}
     else:
         meta = {}
 
@@ -30,7 +27,7 @@
     try:
         lock = repo.lock()
         t = repo.transaction(b'commit')
-        node = fl.add(text, meta, t, 0, nullid, nullid)
+        node = fl.add(text, meta, t, 0, repo.nullid, repo.nullid)
         return node
     finally:
         if t:
diff -r 5fa019ceb499 -r d55b71393907 tests/test-parseindex2.py
--- a/tests/test-parseindex2.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-parseindex2.py	Mon Mar 29 01:52:06 2021 +0200
@@ -14,8 +14,8 @@
 from mercurial.node import (
     bin,
     hex,
-    nullid,
     nullrev,
+    sha1nodeconstants,
 )
 from mercurial import (
     policy,
@@ -40,7 +40,7 @@
     s = 64
     cache = None
     index = []
-    nodemap = {nullid: nullrev}
+    nodemap = {sha1nodeconstants.nullid: nullrev}
     n = off = 0
 
     l = len(data) - s
@@ -227,7 +227,7 @@
 
         ix = parsers.parse_index2(data_inlined, True)[0]
         for i, r in enumerate(ix):
-            if r[7] == nullid:
+            if r[7] == sha1nodeconstants.nullid:
                 i = -1
             try:
                 self.assertEqual(
@@ -240,7 +240,7 @@
                 break
 
     def testminusone(self):
-        want = (0, 0, 0, -1, -1, -1, -1, nullid)
+        want = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid)
         index, junk = parsers.parse_index2(data_inlined, True)
         got = index[-1]
         self.assertEqual(want, got)  # inline data
diff -r 5fa019ceb499 -r d55b71393907 tests/test-remotefilelog-datapack.py
--- a/tests/test-remotefilelog-datapack.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-remotefilelog-datapack.py	Mon Mar 29 01:52:06 2021 +0200
@@ -16,7 +16,7 @@
 
 # Load the local remotefilelog, not the system one
 sys.path[0:0] = [os.path.join(os.path.dirname(__file__), '..')]
-from mercurial.node import nullid
+from mercurial.node import sha1nodeconstants
 from mercurial import policy
 
 if not policy._packageprefs.get(policy.policy, (False, False))[1]:
@@ -63,7 +63,14 @@
 
     def createPack(self, revisions=None, packdir=None):
         if revisions is None:
-            revisions = [(b"filename", self.getFakeHash(), nullid, b"content")]
+            revisions = [
+                (
+                    b"filename",
+                    self.getFakeHash(),
+                    sha1nodeconstants.nullid,
+                    b"content",
+                )
+            ]
 
         if packdir is None:
             packdir = self.makeTempDir()
@@ -86,7 +93,7 @@
         filename = b"foo"
         node = self.getHash(content)
 
-        revisions = [(filename, node, nullid, content)]
+        revisions = [(filename, node, sha1nodeconstants.nullid, content)]
         pack = self.createPack(revisions)
         if self.paramsavailable:
             self.assertEqual(
@@ -126,7 +133,7 @@
         """Test putting multiple delta blobs into a pack and read the chain."""
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             content = b"abcdef%d" % i
             node = self.getHash(content)
@@ -157,7 +164,7 @@
             for j in range(random.randint(1, 100)):
                 content = b"content-%d" % j
                 node = self.getHash(content)
-                lastnode = nullid
+                lastnode = sha1nodeconstants.nullid
                 if len(filerevs) > 0:
                     lastnode = filerevs[random.randint(0, len(filerevs) - 1)]
                 filerevs.append(node)
@@ -185,7 +192,9 @@
                 b'Z': b'random_string',
                 b'_': b'\0' * i,
             }
-            revisions.append((filename, node, nullid, content, meta))
+            revisions.append(
+                (filename, node, sha1nodeconstants.nullid, content, meta)
+            )
         pack = self.createPack(revisions)
         for name, node, x, content, origmeta in revisions:
             parsedmeta = pack.getmeta(name, node)
@@ -198,7 +207,7 @@
         """Test the getmissing() api."""
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             content = b"abcdef%d" % i
             node = self.getHash(content)
@@ -225,7 +234,7 @@
         pack = self.createPack()
 
         try:
-            pack.add(b'filename', nullid, b'contents')
+            pack.add(b'filename', sha1nodeconstants.nullid, b'contents')
             self.assertTrue(False, "datapack.add should throw")
         except RuntimeError:
             pass
@@ -264,7 +273,9 @@
             content = filename
             node = self.getHash(content)
             blobs[(filename, node)] = content
-            revisions.append((filename, node, nullid, content))
+            revisions.append(
+                (filename, node, sha1nodeconstants.nullid, content)
+            )
 
         pack = self.createPack(revisions)
         if self.paramsavailable:
@@ -288,7 +299,12 @@
 
         for i in range(numpacks):
             chain = []
-            revision = (b'%d' % i, self.getFakeHash(), nullid, b"content")
+            revision = (
+                b'%d' % i,
+                self.getFakeHash(),
+                sha1nodeconstants.nullid,
+                b"content",
+            )
 
             for _ in range(revisionsperpack):
                 chain.append(revision)
@@ -346,7 +362,9 @@
                 filename = b"filename-%d" % i
                 content = b"content-%d" % i
                 node = self.getHash(content)
-                revisions.append((filename, node, nullid, content))
+                revisions.append(
+                    (filename, node, sha1nodeconstants.nullid, content)
+                )
 
             path = self.createPack(revisions).path
 
diff -r 5fa019ceb499 -r d55b71393907 tests/test-remotefilelog-histpack.py
--- a/tests/test-remotefilelog-histpack.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-remotefilelog-histpack.py	Mon Mar 29 01:52:06 2021 +0200
@@ -13,7 +13,7 @@
 
 import silenttestrunner
 
-from mercurial.node import nullid
+from mercurial.node import sha1nodeconstants
 from mercurial import (
     pycompat,
     ui as uimod,
@@ -59,8 +59,8 @@
                 (
                     b"filename",
                     self.getFakeHash(),
-                    nullid,
-                    nullid,
+                    sha1nodeconstants.nullid,
+                    sha1nodeconstants.nullid,
                     self.getFakeHash(),
                     None,
                 )
@@ -119,10 +119,19 @@
         """
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             node = self.getFakeHash()
-            revisions.append((filename, node, lastnode, nullid, nullid, None))
+            revisions.append(
+                (
+                    filename,
+                    node,
+                    lastnode,
+                    sha1nodeconstants.nullid,
+                    sha1nodeconstants.nullid,
+                    None,
+                )
+            )
             lastnode = node
 
         # revisions must be added in topological order, newest first
@@ -148,17 +157,17 @@
         for i in range(100):
             filename = b"filename-%d" % i
             entries = []
-            p2 = nullid
-            linknode = nullid
+            p2 = sha1nodeconstants.nullid
+            linknode = sha1nodeconstants.nullid
             for j in range(random.randint(1, 100)):
                 node = self.getFakeHash()
-                p1 = nullid
+                p1 = sha1nodeconstants.nullid
                 if len(entries) > 0:
                     p1 = entries[random.randint(0, len(entries) - 1)]
                 entries.append(node)
                 revisions.append((filename, node, p1, p2, linknode, None))
                 allentries[(filename, node)] = (p1, p2, linknode)
-                if p1 == nullid:
+                if p1 == sha1nodeconstants.nullid:
                     ancestorcounts[(filename, node)] = 1
                 else:
                     newcount = ancestorcounts[(filename, p1)] + 1
@@ -182,10 +191,19 @@
     def testGetNodeInfo(self):
         revisions = []
         filename = b"foo"
-        lastnode = nullid
+        lastnode = sha1nodeconstants.nullid
         for i in range(10):
             node = self.getFakeHash()
-            revisions.append((filename, node, lastnode, nullid, nullid, None))
+            revisions.append(
+                (
+                    filename,
+                    node,
+                    lastnode,
+                    sha1nodeconstants.nullid,
+                    sha1nodeconstants.nullid,
+                    None,
+                )
+            )
             lastnode = node
 
         pack = self.createPack(revisions)
@@ -233,7 +251,14 @@
         pack = self.createPack()
 
         try:
-            pack.add(b'filename', nullid, nullid, nullid, nullid, None)
+            pack.add(
+                b'filename',
+                sha1nodeconstants.nullid,
+                sha1nodeconstants.nullid,
+                sha1nodeconstants.nullid,
+                sha1nodeconstants.nullid,
+                None,
+            )
             self.assertTrue(False, "historypack.add should throw")
         except RuntimeError:
             pass
diff -r 5fa019ceb499 -r d55b71393907 tests/test-revlog-raw.py
--- a/tests/test-revlog-raw.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/test-revlog-raw.py	Mon Mar 29 01:52:06 2021 +0200
@@ -6,7 +6,6 @@
 import hashlib
 import sys
 
-from mercurial.node import nullid
 from mercurial import (
     encoding,
     revlog,
@@ -93,7 +92,7 @@
     """
     nextrev = len(rlog)
     p1 = rlog.node(nextrev - 1)
-    p2 = nullid
+    p2 = rlog.nullid
     if isext:
         flags = revlog.REVIDX_EXTSTORED
     else:
@@ -127,7 +126,7 @@
     class dummychangegroup(object):
         @staticmethod
         def deltachunk(pnode):
-            pnode = pnode or nullid
+            pnode = pnode or rlog.nullid
             parentrev = rlog.rev(pnode)
             r = parentrev + 1
             if r >= len(rlog):
@@ -142,7 +141,7 @@
             return {
                 b'node': rlog.node(r),
                 b'p1': pnode,
-                b'p2': nullid,
+                b'p2': rlog.nullid,
                 b'cs': rlog.node(rlog.linkrev(r)),
                 b'flags': rlog.flags(r),
                 b'deltabase': rlog.node(deltaparent),
@@ -183,7 +182,7 @@
     dlog = newrevlog(destname, recreate=True)
     for r in rlog:
         p1 = rlog.node(r - 1)
-        p2 = nullid
+        p2 = rlog.nullid
         if r == 0 or (rlog.flags(r) & revlog.REVIDX_EXTSTORED):
             text = rlog.rawdata(r)
             cachedelta = None
diff -r 5fa019ceb499 -r d55b71393907 tests/testlib/ext-sidedata.py
--- a/tests/testlib/ext-sidedata.py	Mon Apr 19 20:38:52 2021 -0400
+++ b/tests/testlib/ext-sidedata.py	Mon Mar 29 01:52:06 2021 +0200
@@ -10,10 +10,7 @@
 import hashlib
 import struct
 
-from mercurial.node import (
-    nullid,
-    nullrev,
-)
+from mercurial.node import nullrev
 from mercurial import (
     extensions,
     requirements,
@@ -46,7 +43,7 @@
         return text, sd
     if self.version & 0xFFFF != 2:
         return text, sd
-    if nodeorrev != nullrev and nodeorrev != nullid:
+    if nodeorrev != nullrev and nodeorrev != self.nullid:
         cat1 = sd.get(sidedata.SD_TEST1)
         if cat1 is not None and len(text) != struct.unpack('>I', cat1)[0]:
             raise RuntimeError('text size mismatch')