diff mercurial/scmutil.py @ 33088:65cadeea6c22

scmutil: add a cleanupnodes method for developers

It's now common that an old node gets replaced by zero or more new nodes,
that could happen with amend, rebase, histedit, etc. And it's a common
requirement to do bookmark movements, strip or obsolete nodes and even
moving working copy parent.

Previously, amend, rebase, history have their own logic doing the above.
This patch is an attempt to unify them and future code.

This enables new developers to be able to do "replace X with Y" thing
correctly, without any knowledge about bookmarks, strip or obsstore.

The next step will be migrating rebase to the new API, so it works inside a
transaction, and its code could be simplified.

--- a/mercurial/scmutil.py	Sun Jun 25 10:38:45 2017 -0700
+++ b/mercurial/scmutil.py	Sun Jun 25 13:31:56 2017 -0700
@@ -16,6 +16,8 @@
 
 from .i18n import _
 from .node import (
+    hex,
+    nullid,
     wdirid,
     wdirrev,
 )
@@ -24,6 +26,7 @@
     encoding,
     error,
     match as matchmod,
+    obsolete,
     pathutil,
     phases,
     pycompat,
@@ -561,6 +564,68 @@
 
     return fullorigpath + ".orig"
 
+def cleanupnodes(repo, mapping, operation):
+    """do common cleanups when old nodes are replaced by new nodes
+
+    That includes writing obsmarkers or stripping nodes, and moving bookmarks.
+    (we might also want to move working directory parent in the future)
+
+    mapping is {oldnode: [newnode]} or a iterable of nodes if they do not have
+    replacements. operation is a string, like "rebase".
+    """
+    if not util.safehasattr(mapping, 'items'):
+        mapping = {n: () for n in mapping}
+
+    with repo.transaction('cleanup') as tr:
+        # Move bookmarks
+        bmarks = repo._bookmarks
+        bmarkchanged = False
+        for oldnode, newnodes in mapping.items():
+            oldbmarks = repo.nodebookmarks(oldnode)
+            if not oldbmarks:
+                continue
+            bmarkchanged = True
+            if len(newnodes) > 1:
+                heads = list(repo.set('heads(%ln)', newnodes))
+                if len(heads) != 1:
+                    raise error.ProgrammingError(
+                        'cannot figure out bookmark movement')
+                newnode = heads[0].node()
+            elif len(newnodes) == 0:
+                # move bookmark backwards
+                roots = list(repo.set('max((::%n) - %ln)', oldnode,
+                                      list(mapping)))
+                if roots:
+                    newnode = roots[0].node()
+                else:
+                    newnode = nullid
+            else:
+                newnode = newnodes[0]
+            repo.ui.debug('moving bookmarks %r from %s to %s\n' %
+                          (oldbmarks, hex(oldnode), hex(newnode)))
+            for name in oldbmarks:
+                bmarks[name] = newnode
+        if bmarkchanged:
+            bmarks.recordchange(tr)
+
+        # Obsolete or strip nodes
+        if obsolete.isenabled(repo, obsolete.createmarkersopt):
+            # If a node is already obsoleted, and we want to obsolete it
+            # without a successor, skip that obssolete request since it's
+            # unnecessary. That's the "if s or not isobs(n)" check below.
+            # Also sort the node in topology order, that might be useful for
+            # some obsstore logic.
+            # NOTE: the filtering and sorting might belong to createmarkers.
+            isobs = repo.obsstore.successors.__contains__
+            sortfunc = lambda ns: repo.changelog.rev(ns[0])
+            rels = [(repo[n], (repo[m] for m in s))
+                    for n, s in sorted(mapping.items(), key=sortfunc)
+                    if s or not isobs(n)]
+            obsolete.createmarkers(repo, rels, operation=operation)
+        else:
+            from . import repair # avoid import cycle
+            repair.delayedstrip(repo.ui, repo, list(mapping), operation)
+
 def addremove(repo, matcher, prefix, opts=None, dry_run=None, similarity=None):
     if opts is None:
         opts = {}