revpair: smartset compatibility
Since recent revset changes, revrange now return a smartset. This smart set
probably does not support indexing (_addset does not). This led to crash.
Instead when the smartset is ordered we use the `min` and `max` method of
smart set. Otherwise we turn is into a list and use indexing on it.
The tests have been updated to catch such regression.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..