perf: have a generic "clearstorecache" function There are multiple places where we will want to purge some store cache. So we promote the existing _clearobsstore function to a something reusable.

localrepo: move filtername to __init__ This is obviously an instance attribute, not a type attribute. The modern Python style is to use __init__ for defining these. This exposes statichttprepo as inheriting from localrepository without calling its __init__. As a result, its __init__ defines a lot of variables that methods on localrepository's methods need. But factoring the common bits into a separate class is for another day.

obsolete: move obsstore creation logic from localrepo This code has more to do with obsolete.py than localrepo.py. Let's move it there.

match: allow pats to be None match.match already interprets "!bool(patterns)" as matching everything (but includes and excludes still apply). We might as well allow None, which lets us simplify some callers a bit. I originally wrote this patch while trying to change match.match(patterns=[]) to mean to match no patterns. This patch is one step towards that goal. I'm not sure it'll be worth the effort to go all the way there, but I think this patch still makes sense on its own.

tests: add a test for installing hg with pip in a virtualenv Since we're doing so much clever junk in our setup.py, let's have a test that exercises it. Thanks to Matt Harbison for testing this on Windows and verifying that installenv/*/hg would work as a way to work around bin being called Scripts on Windows.

hghave: add check for virtualenv