revlog.py: always return tuples from parents and parentrevs
There's at least one place doing parentrevs(rev) != (rev-1, -1),
which is always true with revlog v0, since parentrevs returns a list
in this case.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
echo % init
hg init a
cd a
echo % commit
echo 'base' > base
hg ci -Ambase -d '1 0'
echo % qnew mqbase
hg qnew -mmqbase mqbase
echo % qrefresh
echo 'patched' > base
hg qrefresh
echo % qdiff
hg qdiff | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" \
-e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/"
echo % qdiff dirname
hg qdiff . | sed -e "s/\(+++ [a-zA-Z0-9_/.-]*\).*/\1/" \
-e "s/\(--- [a-zA-Z0-9_/.-]*\).*/\1/"