convert: fix mercurial_sink.putcommit Changeset 4ebc8693ce72 added some code to putcommit to avoid creating a revision that touches no files, but this can break regular conversions from some repositories: - conceptually, since we're converting a repo, we should try to make the new hg repo as similar as possible to the original repo - we should create a new changeset, even if the original revision didn't touch any files (maybe the commit message had some important bit); - even if a "regular" revision that doesn't touch any file may seem weird (and maybe even broken), it's completely legitimate for a merge revision to not touch any file, and, if we just skip it, the converted repo will end up with wrong history and possibly an extra head. As an example, say the crew and main hg repos are sync'ed. Somebody sends an important patch to the mailing list. Matt quickly applies and pushes it. But at the same time somebody also applies it to crew and pushes it. Suppose the commit message ended up being a bit different (say, there was a typo and somebody didn't fix it) or that the date ended up being different (because of different patch-applying scripts): the changeset hashes will be different, but the manifests will be the same. Since both changesets were pushed to public repos, it's hard to recall them. If both are merged, the manifest from the resulting merge revision will have the exact same contents as its parents - i.e. the merge revision really doesn't touch any file at all. To keep the file filtering stuff "working", the generic code was changed to skip empty revisions if we're filtering the repo, fixing a bug in the process (we want parents[0] instead of tip).

adding bar
adding foo
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
% start imerge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
U foo
foo
bar
bar
bar
% status -v
merging e6da46716401 and 30d266f502e7
U foo (foo2)
% next
foo
% merge next
merging foo and foo2
all conflicts resolved
% unresolve
% merge foo
merging foo and foo2
all conflicts resolved
% save
% load
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
R foo
all conflicts resolved
foo
changeset:   3:fa9a6defdcaf
tag:         tip
parent:      2:e6da46716401
parent:      1:30d266f502e7
user:        test
date:        Thu Jan 01 00:00:03 1970 +0000
files:       foo foo2
description:
merged


% nothing to merge
abort: there is nothing to merge - use "hg update" instead