convert: add a mode where mercurial_sink skips empty revisions.
The getchanges function of some converter_source classes can return
some false positives. I.e. they sometimes claim that a file "foo"
was changed in some revision, even though its contents are still the
same.
convert_svn is particularly bad, but I think this can also happen with
convert_cvs and, at least in theory, with mercurial_source.
For regular conversions this is not really a problem - as long as
getfile returns the right contents, we'll get a converted revision
with the right contents. But when we use --filemap, this could lead
to superfluous revisions being converted.
Instead of fixing every converter_source, I decided to change
mercurial_sink to work around this problem.
When --filemap is used, we're interested only in revisions that touch
some specific files. If a revision doesn't change any of these files,
then we're not interested in it (at least for revisions with a single
parent; merges are special).
For mercurial_sink, we abuse this property and rollback a commit if
the manifest text hasn't changed. This avoids duplicating the logic
from localrepo.filecommit to detect unchanged files.
# should fail - foo is not managed
foo: not copying - file is not managed
abort: no files to copy
? foo
# dry-run; print a warning that this is not a real copy; foo is added
foo has not been committed yet, so no copy data will be stored for bar.
A foo
# should print a warning that this is not a real copy; bar is added
foo has not been committed yet, so no copy data will be stored for bar.
A bar
# should print a warning that this is not a real copy; foo is added
bar has not been committed yet, so no copy data will be stored for foo.
A foo
# dry-run; should show that foo is clean
C foo
# should show copy
A bar
foo
# shouldn't show copy
# should match
rev offset length base linkrev nodeid p1 p2
0 0 5 0 0 2ed2a3912a0b 000000000000 000000000000
bar renamed from foo:2ed2a3912a0b24502043eae84ee4b279c18b90dd
# should not be renamed
bar not renamed
# should show copy
M bar
foo
# should show no parents for tip
rev offset length base linkrev nodeid p1 p2
0 0 69 0 1 6ca237634e1f 000000000000 000000000000
1 69 6 1 2 7a1ff8e75f5b 6ca237634e1f 000000000000
2 75 82 1 3 243dfe60f3d9 000000000000 000000000000
# should match
rev offset length base linkrev nodeid p1 p2
0 0 5 0 0 2ed2a3912a0b 000000000000 000000000000
1 5 7 1 2 dd12c926cf16 2ed2a3912a0b 000000000000
bar renamed from foo:dd12c926cf165e3eb4cf87b084955cb617221c17
# should show no copies
# copy --after on an added file
A baz
bar
# foo was clean:
C foo
# but it's considered modified after a copy --after --force
M foo
bar