revset: fix O(2^n) perf regression in addset hg log -r 1 ... -r 100 was never returning due to a regression in the way addset computes __nonzero__. It used 'bool(self._r1 or self._r2)' which required executing self._r1.__nonzero__ twice (once for the or, once for the bool). hg log with a lot of -r's happens to build a one sided addset tree of N length, which ends up being 2^N performance. This patch fixes it by converting to bool before or'ing. This problem can be repro'd with something as simple as: hg log `for x in $(seq 1 50) ; do echo "-r $x "; done` Adding '1 + 2 + ... + 20' to the revsetbenchmark.txt didn't seem to repro the problem, so I wasn't able to add a revset benchmark for this issue.

#!/usr/bin/python
from mercurial.ui import ui
from mercurial.localrepo import localrepository
from mercurial.commands import add, commit, status

u = ui()

print '% creating repo'
repo = localrepository(u, '.', create=True)

f = open('test.py', 'w')
try:
    f.write('foo\n')
finally:
    f.close

print '% add and commit'
add(u, repo, 'test.py')
commit(u, repo, message='*')
status(u, repo, clean=True)


print '% change'
f = open('test.py', 'w')
try:
    f.write('bar\n')
finally:
    f.close()

# this would return clean instead of changed before the fix
status(u, repo, clean=True, modified=True)