revlog: fix resolution of revlog version 0
This partially backs out
cecf3f8bccd3, "revlog: always process opener options."
My understanding is that if there's no "revlog1" nor "revlog2" in .hg/requires,
the repository should stick to the v0 format. The reasoning is briefly
described in
31a5973fcf96, "revlog: get rid of defversion."
Maybe we can drop support for missing opener options, but I didn't do that
in this patch.
#require no-pure
A script to generate nasty diff worst-case scenarios:
$ cat > s.py <<EOF
> import random
> for x in range(100000):
> print
> if random.randint(0, 100) >= 50:
> x += 1
> print(hex(x))
> EOF
$ hg init a
$ cd a
Check in a big file:
$ "$PYTHON" ../s.py > a
$ hg ci -qAm0
Modify it:
$ "$PYTHON" ../s.py > a
Time a check-in, should never take more than 10 seconds user time:
$ hg ci --time -m1
time: real .* secs .user [0-9][.].* sys .* (re)