hg: allow hg.parseurl(url, None) In many places hg.parseurl is called with a url and "opts.get('rev')", suggesting the second, optional argument can be None. Because opts['rev'] usually defaults to [] this never happens in practice. However, extensions don't necessarily behave the same, but do copy this pattern. Also, include wider hg.parseurl tests, beyond a demonstration of the problem.

--- a/mercurial/hg.py	Fri Apr 24 17:00:18 2009 -0500
+++ b/mercurial/hg.py	Fri Apr 24 18:17:42 2009 +0200
@@ -25,7 +25,7 @@
 
     url, branch = url.split('#', 1)
     checkout = revs and revs[-1] or branch
-    return url, revs + [branch], checkout
+    return url, (revs or []) + [branch], checkout
 
 schemes = {
     'bundle': bundlerepo,