[PATCH] strip: invalidate phase cache after stripping changeset (issue5235)

[Laurent Charignon]

# HG changeset patch
# User Laurent Charignon <lcharignon at fb.com>
# Date 1462971969 25200
#      Wed May 11 06:06:09 2016 -0700
# Node ID fd005346d3c86b65c690f8f987e05f44ec4ec02f
# Parent  df838803c1d487e4601f96c6cfd85e6ad4f6291f
strip: invalidate phase cache after stripping changeset (issue5235)

When we remove a changeset from the changelog, the phase cache must be
invalidated, otherwise it could refer to changesets that are no longer in the
repo.

To reproduce the failure, I created an extension querying the phase cache after
the strip transaction is over.

To do that, I stripped two commits with a bookmark on one of them to force
another transaction (we open a transaction for moving bookmarks)
after the strip transaction.

Without the fix in this patch, the test leads to a stacktrace showing the issue:
      repair.strip(ui, repo, revs, backup)
    File "/Users/lcharignon/facebook-hg-rpms/hg-crew/mercurial/repair.py", line 205, in strip
      tr.close()
    File "/Users/lcharignon/facebook-hg-rpms/hg-crew/mercurial/transaction.py", line 44, in _active
      return func(self, *args, **kwds)
    File "/Users/lcharignon/facebook-hg-rpms/hg-crew/mercurial/transaction.py", line 490, in close
      self._postclosecallback[cat](self)
    File "$TESTTMP/crashstrip2.py", line 4, in test
      [repo.changelog.node(r) for r in repo.revs("not public()")]
    File "/Users/lcharignon/facebook-hg-rpms/hg-crew/mercurial/changelog.py", line 337, in node
      return super(changelog, self).node(rev)
    File "/Users/lcharignon/facebook-hg-rpms/hg-crew/mercurial/revlog.py", line 377, in node
      return self.index[rev][7]
  IndexError: revlog index out of range

The situation was encountered in inhibit (evolve's repo) where we would crash
following the volatile set invalidation submitted by Augie in
e6f490e328635312ee214a12bc7fd3c7d46bf9ce. Before his patch the issue was masked
as we were not accessing the phasecache after stripping a revision.

This bug uncovered another but in histedit (see explanation in issue5235).
I changed the histedit test accordingly to avoid fixing two things at once.

diff --git a/mercurial/repair.py b/mercurial/repair.py
--- a/mercurial/repair.py
+++ b/mercurial/repair.py
@@ -165,6 +165,7 @@
 
             tr.startgroup()
             cl.strip(striprev, tr)
+            repo._phasecache.invalidate()
             mfst.strip(striprev, tr)
             for fn in files:
                 repo.file(fn).strip(striprev, tr)
diff --git a/tests/test-histedit-fold.t b/tests/test-histedit-fold.t
--- a/tests/test-histedit-fold.t
+++ b/tests/test-histedit-fold.t
@@ -468,14 +468,14 @@
 #endif
   $ hg histedit 6c795aa153cb --config hooks.commit="echo commit $NODE" --commands - 2>&1 << EOF | fixbundle
   > pick 199b6bb90248 b
+  > pick 6c795aa153cb a
   > fold a1a953ffb4b0 c
-  > pick 6c795aa153cb a
   > EOF
-  commit 9599899f62c05f4377548c32bf1c9f1a39634b0c
+  commit 16b87e97178dde2af2f3c6f6ddda882292f21d13
 
   $ hg logt
-  1:9599899f62c0 a
-  0:79b99e9c8e49 b
+  1:32458953dcb2 a
+  0:16b87e97178d b
 
   $ echo "foo" > amended.txt
   $ hg add amended.txt
@@ -492,11 +492,11 @@
   $ echo foo >> foo
   $ hg ci -m foo3
   $ hg logt
-  4:21679ff7675c foo3
-  3:b7389cc4d66e foo2
-  2:0e01aeef5fa8 foo1
-  1:578c7455730c a
-  0:79b99e9c8e49 b
+  4:52350bf3559e foo3
+  3:e72786ea58ec foo2
+  2:60447e897f97 foo1
+  1:7fc781383476 a
+  0:16b87e97178d b
   $ cat > "$TESTTMP/editor.sh" <<EOF
   > echo ran editor >> "$TESTTMP/editorlog.txt"
   > cat \$1 >> "$TESTTMP/editorlog.txt"
@@ -504,15 +504,15 @@
   > echo merged foos > \$1
   > EOF
   $ HGEDITOR="sh \"$TESTTMP/editor.sh\"" hg histedit 1 --commands - 2>&1 <<EOF | fixbundle
-  > pick 578c7455730c 1 a
-  > pick 0e01aeef5fa8 2 foo1
-  > fold b7389cc4d66e 3 foo2
-  > fold 21679ff7675c 4 foo3
+  > pick 7fc781383476 1 a
+  > pick 60447e897f97 2 foo1
+  > fold e72786ea58ec 3 foo2
+  > fold 52350bf3559e 4 foo3
   > EOF
   $ hg logt
-  2:e8bedbda72c1 merged foos
-  1:578c7455730c a
-  0:79b99e9c8e49 b
+  2:be62bdec37b8 merged foos
+  1:7fc781383476 a
+  0:16b87e97178d b
 Editor should have run only once
   $ cat $TESTTMP/editorlog.txt
   ran editor
diff --git a/tests/test-strip.t b/tests/test-strip.t
--- a/tests/test-strip.t
+++ b/tests/test-strip.t
@@ -838,6 +838,41 @@
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     mergeCD
   
+Check that the phase cache is properly invalidated after a strip with bookmark.
+
+  $ cat > ../stripstalephasecache.py << EOF
+  > from mercurial import extensions, localrepo
+  > def transactioncallback(orig, repo, desc, *args, **kwargs):
+  >     def test(transaction):
+  >         # observe cache inconsistency
+  >         try:
+  >             [repo.changelog.node(r) for r in repo.revs("not public()")]
+  >         except IndexError:
+  >             repo.ui.status("Index error!\n")
+  >     transaction = orig(repo, desc, *args, **kwargs)
+  >     # warm up the phase cache
+  >     list(repo.revs("not public()"))
+  >     if desc != 'strip':
+  >          transaction.addpostclose("phase invalidation test", test)
+  >     return transaction
+  > def extsetup(ui):
+  >     extensions.wrapfunction(localrepo.localrepository, "transaction",
+  >                             transactioncallback)
+  > EOF
+  $ hg up -C 2
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ echo k > k
+  $ hg add k
+  $ hg commit -m commitK
+  $ echo l > l
+  $ hg add l
+  $ hg commit -m commitL
+  $ hg book -r tip blah
+  $ hg strip ".^" --config extensions.crash=$TESTTMP/stripstalephasecache.py
+  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
+  saved backup bundle to $TESTTMP/issue4736/.hg/strip-backup/8f0b4384875c-4fa10deb-backup.hg (glob)
+  $ hg up -C 1
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 Error during post-close callback of the strip transaction
 (They should be gracefully handled and reported)