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
# b51a8138292a introduced a regression where we would mention in the
# changelog executable files added by the second parent of a merge.
# Test that that doesn't happen anymore

"$TESTDIR/hghave" execbit || exit 80

hg init repo
cd repo
echo foo > foo
hg ci -qAm 'add foo' -d '0 0'

echo bar > bar
chmod +x bar
hg ci -qAm 'add bar' -d '0 0'
echo '% manifest of p2:'
hg manifest
echo

hg up -qC 0
echo >> foo
hg ci -m 'change foo' -d '0 0'
echo '% manifest of p1:'
hg manifest

hg merge
hg ci -m 'merge' -d '0 0'

echo '% this should not mention bar:'
hg tip -v

hg debugindex .hg/store/data/bar.i