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

hg init repo1
cd repo1
mkdir a b a/1 b/1 b/2
touch in_root a/in_a b/in_b a/1/in_a_1 b/1/in_b_1 b/2/in_b_2
echo "hg status in repo root:"
hg status
echo "hg status . in repo root:"
hg status .
for dir in a b a/1 b/1 b/2; do
    echo "hg status in $dir:"
    hg status --cwd "$dir"
    echo "hg status . in $dir:"
    hg status --cwd "$dir" .
    echo "hg status .. in $dir:"
    hg status --cwd "$dir" ..
done
cd ..

hg init repo2
cd repo2
touch modified removed deleted ignored
echo "ignored" > .hgignore
hg ci -A -m 'initial checkin' -d "1000000 0"
sleep 1 # make sure mtime is changed
touch modified added unknown ignored
hg add added
hg remove removed
rm deleted
echo "hg status:"
hg status
echo "hg status modified added removed deleted unknown never-existed ignored:"
hg status modified added removed deleted unknown never-existed ignored
hg copy modified copied
echo "hg status -C:"
hg status -C
echo "hg status -A:"
hg status -A