histedit: read state from histeditstate
Read the state in histeditstate. This allows us to correctly update
internal variables when necessary without having to recreate a new
state. When we read a state in _histedit state while we will already
have state passed from histedit(), we can read the state in place
and don't have to merge two histeditstates.
$ hg init
$ touch unknown
$ touch a
$ hg add a
$ hg ci -m "1"
$ touch b
$ hg add b
$ hg ci -m "2"
Should show unknown
$ hg status
? unknown
$ hg revert -r 0 --all
removing b
Should show unknown and b removed
$ hg status
R b
? unknown
Should show a and unknown
$ ls
a
unknown