view tests/test-issue2137.t @ 24710:909ee6b2a024

lazymanifest: prevent leak when updating an entry more than once

__setitem__ on the lazymanifest C type wasn't checking to see if a
line had previously been malloced before replacing it, leading to
leaks if files got updated multiple times in the course of a task.

I was able to reproduce the leak with this change to test-manifest.py:

diff --git a/tests/test-manifest.py b/tests/test-manifest.py
--- a/tests/test-manifest.py
+++ b/tests/test-manifest.py
@@ -456,6 +456,16 @@ class basemanifesttests(object):
                 ['a/b/c/bar.txt', 'a/b/c/foo.txt', 'a/b/d/ten.txt'],
                 m2.keys())

+    def testManifestSetItem(self):
+        m = self.parsemanifest('')
+        for x in range(3):
+            m['file%d' % x] = BIN_HASH_1
+        for x in range(3):
+            m['file%d' % x] = BIN_HASH_2
+        import time
+        time.sleep(4)
+
+

along with the commands:

 $ make local
 $ PYTHONPATH=. SILENT_BE_NOISY=1 python tests/test-manifest.py testmanifestdict.testManifestSetItem &
 $ sleep 4
 $ leaks $(jobs -p | tee /dev/stderr | awk '{print $3}')
 $ wait

in an interactive shell on OS X. As far as I can tell, it had to be an
interactive shell so that I could get the pid of the test run using
the jobs builtin. Prior to this change, I was leaking several strings,
and after this change leaks reports no leaks.

I thought there was a bug filed for this in bugzilla, but I can't find
it either in bugzilla or by searching my email.

http://mercurial.selenic.com/bts/issue2137

Setup:

create a little extension that has 3 side-effects:
1) ensure changelog data is not inlined
2) make revlog to use lazyparser
3) test that repo.lookup() works
1 and 2 are preconditions for the bug; 3 is the bug.

  $ cat > commitwrapper.py <<EOF
  > from mercurial import extensions, node, revlog
  > 
  > def reposetup(ui, repo):
  >     class wraprepo(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             result = super(wraprepo, self).commit(*args, **kwargs)
  >             tip1 = node.short(repo.changelog.tip())
  >             tip2 = node.short(repo.lookup(tip1))
  >             assert tip1 == tip2
  >             ui.write('new tip: %s\n' % tip1)
  >             return result
  >     repo.__class__ = wraprepo
  > 
  > def extsetup(ui):
  >     revlog._maxinline = 8             # split out 00changelog.d early
  >     revlog._prereadsize = 8           # use revlog.lazyparser
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > commitwrapper = `pwd`/commitwrapper.py
  > EOF

  $ hg init repo1
  $ cd repo1
  $ echo a > a
  $ hg commit -A -m'add a with a long commit message to make the changelog a bit bigger'
  adding a
  new tip: 553596fad57b

Test that new changesets are visible to repo.lookup():

  $ echo a >> a
  $ hg commit -m'one more commit to demonstrate the bug'
  new tip: 799ae3599e0e

  $ hg tip
  changeset:   1:799ae3599e0e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     one more commit to demonstrate the bug
  

  $ cd ..