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.
adding foo
adding bar
adding baz/bletch
test-archive-TIP/.hg_archival.txt
test-archive-TIP/bar
test-archive-TIP/baz/bletch
test-archive-TIP/foo
test-archive-TIP/.hg_archival.txt
test-archive-TIP/bar
test-archive-TIP/baz/bletch
test-archive-TIP/foo
Archive: archive.zip
testing: test-archive-TIP/.hg_archival.txt OK
testing: test-archive-TIP/bar OK
testing: test-archive-TIP/baz/bletch OK
testing: test-archive-TIP/foo OK
No errors detected in compressed data of archive.zip.
test/.hg_archival.txt
test/bar
test/baz/bletch
test/foo
test/.hg_archival.txt
test/bar
test/foo
test-TIP/.hg_archival.txt
test-TIP/bar
test-TIP/baz/bletch
test-TIP/foo
True
abort: archive prefix contains illegal components
Archive: test.zip
testing: test/.hg_archival.txt OK
testing: test/bar OK
testing: test/baz/bletch OK
testing: test/foo OK
No errors detected in compressed data of test.zip.
test-TIP/.hg_archival.txt
test-TIP/bar
test-TIP/baz/bletch
test-TIP/foo
rev-0.tar created
% empty repo
abort: repository has no revisions