convert/svn: make sink recover gracefully from empty changeset
Otherwise when processing a changeset that in fact changes no files
(perhaps due to bug in import from CVS) can get something like:
unexpected svn output:
abort: unable to cope with svn output
Bug report and patch draft by Jesse Glick <jesse.glick@sun.com>
#!/bin/sh
hg init a
cd a
echo a > a
hg add -n
hg st
hg add
hg st
hg forget a
hg add
hg st
echo b > b
hg add -n b
hg st
hg add b || echo "failed to add b"
hg st
echo % should fail
hg add b
hg st
hg ci -m 0 --traceback
echo % should fail
hg add a
echo aa > a
hg ci -m 1
hg up 0
echo aaa > a
hg ci -m 2
hg merge
hg st
echo % should fail
hg add a
hg st
hg resolve -m a
hg ci -m merge
echo % issue683
hg forget a
hg add a
hg st
hg rm a
hg st
echo a > a
hg add a
hg st
hg add c && echo "unexpected addition of missing file"
echo c > c
hg add d c && echo "unexpected addition of missing file"
hg st