# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 1518550532 28800
# Node ID 33275ab5e8379aa6086d33a3efcd723ea7afce6e
# Parent  d031609b3cb7ce1347f7b61e8960267c84926215
revlog: do not use delta for lfs revisions

This is similar to what we have done for changegroups. It is needed to make
sure the delta application code path can assume deltas are always against
vanilla (ex. non-LFS) rawtext so the next fix becomes possible.

Differential Revision: https://phab.mercurial-scm.org/D2068

diff -r d031609b3cb7 -r 33275ab5e837 mercurial/revlog.py
--- a/mercurial/revlog.py	Tue Feb 06 19:08:25 2018 -0800
+++ b/mercurial/revlog.py	Tue Feb 13 11:35:32 2018 -0800
@@ -407,6 +407,9 @@
         for candidaterevs in self._getcandidaterevs(p1, p2, cachedelta):
             nominateddeltas = []
             for candidaterev in candidaterevs:
+                # no delta for rawtext-changing revs (see "candelta" for why)
+                if revlog.flags(candidaterev) & REVIDX_RAWTEXT_CHANGING_FLAGS:
+                    continue
                 candidatedelta = self._builddeltainfo(revinfo, candidaterev, fh)
                 if revlog._isgooddeltainfo(candidatedelta, revinfo.textlen):
                     nominateddeltas.append(candidatedelta)
@@ -2090,7 +2093,14 @@
             deltacomputer = _deltacomputer(self)
 
         revinfo = _revisioninfo(node, p1, p2, btext, textlen, cachedelta, flags)
-        deltainfo = deltacomputer.finddeltainfo(revinfo, fh)
+
+        # no delta for flag processor revision (see "candelta" for why)
+        # not calling candelta since only one revision needs test, also to
+        # avoid overhead fetching flags again.
+        if flags & REVIDX_RAWTEXT_CHANGING_FLAGS:
+            deltainfo = None
+        else:
+            deltainfo = deltacomputer.finddeltainfo(revinfo, fh)
 
         if deltainfo is not None:
             base = deltainfo.base
diff -r d031609b3cb7 -r 33275ab5e837 tests/test-lfs-bundle.t
--- a/tests/test-lfs-bundle.t	Tue Feb 06 19:08:25 2018 -0800
+++ b/tests/test-lfs-bundle.t	Tue Feb 13 11:35:32 2018 -0800
@@ -90,10 +90,7 @@
   ---- Applying src-normal.bundle to dst-normal ----
   OK
   ---- Applying src-normal.bundle to dst-lfs ----
-   X@2: unpacking bcc7d23fa6b7: integrity check failed on data/X.i:2
-   Y@2: unpacking 46017a6640e7: integrity check failed on data/Y.i:2
-  2 integrity errors encountered!
-  (first damaged changeset appears to be 2)
+  CRASHED
   ---- Applying src-lfs.bundle to dst-normal ----
   OK
   ---- Applying src-lfs.bundle to dst-lfs ----
diff -r d031609b3cb7 -r 33275ab5e837 tests/test-revlog-raw.py
--- a/tests/test-revlog-raw.py	Tue Feb 06 19:08:25 2018 -0800
+++ b/tests/test-revlog-raw.py	Tue Feb 13 11:35:32 2018 -0800
@@ -114,6 +114,8 @@
             else:
                 # suboptimal deltaparent
                 deltaparent = min(0, parentrev)
+            if not rlog.candelta(deltaparent, r):
+                deltaparent = -1
             return {'node': rlog.node(r), 'p1': pnode, 'p2': node.nullid,
                     'cs': rlog.node(rlog.linkrev(r)), 'flags': rlog.flags(r),
                     'deltabase': rlog.node(deltaparent),
@@ -151,12 +153,14 @@
     for r in rlog:
         p1 = rlog.node(r - 1)
         p2 = node.nullid
-        if r == 0:
+        if r == 0 or (rlog.flags(r) & revlog.REVIDX_EXTSTORED):
             text = rlog.revision(r, raw=True)
             cachedelta = None
         else:
-            # deltaparent is more interesting if it has the EXTSTORED flag.
-            deltaparent = max([0] + [p for p in range(r - 2) if rlog.flags(p)])
+            # deltaparent cannot have EXTSTORED flag.
+            deltaparent = max([-1] +
+                              [p for p in range(r)
+                               if rlog.flags(p) & revlog.REVIDX_EXTSTORED == 0])
             text = None
             cachedelta = (deltaparent, rlog.revdiff(deltaparent, r))
         flags = rlog.flags(r)
@@ -262,8 +266,9 @@
         result.append((text, rawtext))
 
         # Verify flags like isdelta, isext work as expected
-        if bool(rlog.deltaparent(rev) > -1) != isdelta:
-            abort('rev %d: isdelta is ineffective' % rev)
+        # isdelta can be overridden to False if this or p1 has isext set
+        if bool(rlog.deltaparent(rev) > -1) and not isdelta:
+            abort('rev %d: isdelta is unexpected' % rev)
         if bool(rlog.flags(rev)) != isext:
             abort('rev %d: isext is ineffective' % rev)
     return result