cvsps: use a different tiebreaker to avoid flaky test
After adding some sneaky debug printing[0], I determined that this
test flaked when a CVS commit containing two files starts too close to
the end of a second, thus putting file "a" in one second and "b/c" in
the following second. The secondary sort key meant that these changes
sorted in a different order when the timestamps were different than
they did when they matched. As far as I can tell, CVS walks through
the files in a stable order, so by sorting on the filenames in cvsps
we'll get stable output. It's fine for us to switch from sorting on
the branchpoint as a secondary key because this was already the point
when we didn't care, and we're just trying to break ties in a stable
way. It's unclear to be if having the branchpoint present matters
anymore, but it doesn't really hurt to leave it.
With this change in place, I was able to run test-convert-cvs over 650
times in a row without a failure. test-convert-cvcs-synthetic.t
appears to still be flaky, but I don't think it's *worse* than it was
before - just not better (I observed one flaky failure in 200 runs on
that test).
0: The helpful debug hack ended up being this, in case it's useful to
future flaky test assassins:
--- a/hgext/convert/cvsps.py
+++ b/hgext/convert/cvsps.py
@@ -854,6 +854,8 @@ def debugcvsps(ui, *args, **opts):
ui.write(('Branch: %s\n' % (cs.branch or 'HEAD')))
ui.write(('Tag%s: %s \n' % (['', 's'][len(cs.tags) > 1],
','.join(cs.tags) or '(none)')))
+ if cs.comment == 'ci1' and (cs.id == 6) == bool(cs.branchpoints):
+ ui.write('raw timestamp %r\n' % (cs.date,))
if cs.branchpoints:
ui.write(('Branchpoints: %s \n') %
', '.join(sorted(cs.branchpoints)))
#require killdaemons
$ hgserve() {
> hg serve -a localhost -p $HGPORT1 -d --pid-file=hg.pid \
> -E errors.log -v $@ > startup.log
> # Grepping hg serve stdout would hang on Windows
> grep -v 'listening at' startup.log
> cat hg.pid >> "$DAEMON_PIDS"
> }
$ hg init a
$ hg --encoding utf-8 -R a branch æ
marked working directory as branch \xc3\xa6 (esc)
(branches are permanent and global, did you want a bookmark?)
$ echo foo > a/foo
$ hg -R a ci -Am foo
adding foo
$ hgserve -R a --config web.push_ssl=False --config web.allow_push=* --encoding latin1
$ hg --encoding utf-8 clone http://localhost:$HGPORT1 b
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
updating to branch \xc3\xa6 (esc)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding utf-8 -R b log
changeset: 0:867c11ce77b8
branch: \xc3\xa6 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: foo
$ echo bar >> b/foo
$ hg -R b ci -m bar
$ hg --encoding utf-8 -R b push
pushing to http://localhost:$HGPORT1/
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
$ hg -R a --encoding utf-8 log
changeset: 1:58e7c90d67cb
branch: \xc3\xa6 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: bar
changeset: 0:867c11ce77b8
branch: \xc3\xa6 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: foo
$ "$TESTDIR/killdaemons.py" hg.pid
verify 7e7d56fe4833 (encoding fallback in branchmap to maintain compatibility with 1.3.x)
$ cat <<EOF > oldhg
> import sys
> from mercurial import ui, hg, commands
>
> class StdoutWrapper(object):
> def __init__(self, stdout):
> self._file = stdout
>
> def write(self, data):
> if data == '47\n':
> # latin1 encoding is one %xx (3 bytes) shorter
> data = '44\n'
> elif data.startswith('%C3%A6 '):
> # translate to latin1 encoding
> data = '%%E6 %s' % data[7:]
> self._file.write(data)
>
> def __getattr__(self, name):
> return getattr(self._file, name)
>
> sys.stdout = StdoutWrapper(sys.stdout)
> sys.stderr = StdoutWrapper(sys.stderr)
>
> myui = ui.ui()
> repo = hg.repository(myui, 'a')
> commands.serve(myui, repo, stdio=True, cmdserver=False)
> EOF
$ echo baz >> b/foo
$ hg -R b ci -m baz
$ hg push -R b -e 'python oldhg' ssh://dummy/ --encoding latin1
pushing to ssh://dummy/
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files