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

hglocate()
{
    echo "hg locate $@"
    hg locate "$@"
    ret=$?
    echo
    return $ret
}

mkdir t
cd t
hg init
echo 0 > a
echo 0 > b
echo 0 > t.h
mkdir t
echo 0 > t/x
echo 0 > t/b
echo 0 > t/e.h
mkdir dir.h
echo 0 > dir.h/foo
hg ci -A -m m -d "1000000 0"
touch nottracked
hglocate a && echo locate succeeded || echo locate failed
hglocate NONEXISTENT && echo locate succeeded || echo locate failed
hglocate
hg rm a
hg ci -m m -d "1000000 0"
hglocate a
hglocate NONEXISTENT
hglocate relpath:NONEXISTENT
hglocate
hglocate -r 0 a
hglocate -r 0 NONEXISTENT
hglocate -r 0 relpath:NONEXISTENT
hglocate -r 0
echo % -I/-X with relative path should work
cd t
hglocate
hglocate -I ../t
# test issue294
cd ..
rm -r t
hglocate 't/**'
mkdir otherdir
cd otherdir
hglocate b
hglocate '*.h'
hglocate path:t/x
hglocate 're:.*\.h$'
hglocate -r 0 b
hglocate -r 0 '*.h'
hglocate -r 0 path:t/x
hglocate -r 0 're:.*\.h$'