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 1
adding 2
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
resolving manifests
overwrite None partial False
ancestor 81f4b099af3d local c64f439569a9+ remote 2f8037f47a5c
1: other deleted -> r
1a: remote created -> g
removing 1
getting 1a
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
resolving manifests
overwrite None partial False
ancestor c64f439569a9 local ac7575e3c052+ remote 746e9549ea96
1a: local moved to 1 -> m
merging 1a and 1
my 1a@ac7575e3c052+ other 1@746e9549ea96 ancestor 1@81f4b099af3d
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
resolving manifests
overwrite None partial False
ancestor c64f439569a9 local 746e9549ea96+ remote ac7575e3c052
1: remote moved to 1a -> m
copying 1 to 1a
merging 1 and 1a
my 1@746e9549ea96+ other 1a@2f8037f47a5c ancestor 1@81f4b099af3d
removing 1
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)