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
hg init
echo a > a
hg add a
hg commit -m "test" -d "1000000 0"
hg history
hg tag -d "1000000 0" "bleah"
hg history
echo foo >> .hgtags
hg tag -d "1000000 0" "bleah2" || echo "failed"
hg tag -d "1000000 0" -r 0 "bleah2" 1 || echo "failed"
hg revert .hgtags
hg tag -d "1000000 0" -r 0 "bleah0"
hg tag -l -d "1000000 0" "bleah1" 1
cat .hgtags
cat .hg/localtags
hg update 0
hg tag -d "1000000 0" "foobar"
cat .hgtags
cat .hg/localtags
hg tag -l 'xx
newline'
hg tag -l 'xx:xx'
true