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
"$TESTDIR/hghave" svn svn-bindings || exit 80
fix_path()
{
tr '\\' /
}
echo "[extensions]" >> $HGRCPATH
echo "convert = " >> $HGRCPATH
svnadmin create svn-repo
echo % initial svn import
mkdir t
cd t
echo a > a
cd ..
svnpath=`pwd | fix_path`
# SVN wants all paths to start with a slash. Unfortunately,
# Windows ones don't. Handle that.
expr $svnpath : "\/" > /dev/null
if [ $? -ne 0 ]; then
svnpath='/'$svnpath
fi
svnurl=file://$svnpath/svn-repo/trunk
svn import -m init t $svnurl | fix_path
echo % update svn repository
svn co $svnurl t2 | fix_path
cd t2
echo b >> a
echo b > b
svn add b
svn ci -m changea
cd ..
echo % convert to hg once
hg convert $svnurl
echo % update svn repository again
cd t2
echo c >> a
echo c >> b
svn ci -m changeb
cd ..
echo % test incremental conversion
hg convert $svnurl