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.
#!/bin/sh
# Test that qpush cleans things up if it doesn't complete
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
hg init repo
cd repo
echo foo > foo
hg ci -Am 'add foo' -d '0 0'
touch untracked-file
echo 'syntax: glob' > .hgignore
echo '.hgignore' >> .hgignore
hg qinit
hg qnew patch1
echo >> foo
hg qrefresh -m 'patch 1'
hg qnew patch2
echo bar > bar
hg add bar
hg qrefresh -m 'patch 2'
hg qnew bad-patch
echo >> foo
hg qrefresh
hg qpop -a
python -c 'print "\xe9"' > message
cat .hg/patches/bad-patch >> message
mv message .hg/patches/bad-patch
hg qpush -a && echo 'qpush succeded?!'
hg parents
echo '% bar should be gone; other unknown/ignored files should still be around'
hg status -A