fileset: combine union of basic patterns into single matcher This appears to improve query performance in a big repository than I thought. Writing less Python in a hot loop, faster computation we gain. $ hg files --cwd mozilla-central --time 'set:a* + b* + c* + d* + e*' (orig) time: real 0.670 secs (user 0.640+0.000 sys 0.030+0.000) (new) time: real 0.210 secs (user 0.180+0.000 sys 0.020+0.000)