revset-limit: use boolean testing instead of `len(revs) < 1`
I'm not sure why we wrote it that way. But smartsets have faster/lazier non-zero
testing than length computation.
--- a/mercurial/scmutil.py Tue Oct 07 00:18:08 2014 -0700
+++ b/mercurial/scmutil.py Mon Oct 06 11:43:32 2014 -0700
@@ -478,7 +478,7 @@
return repo[default]
l = revrange(repo, [revspec])
- if len(l) < 1:
+ if not l:
raise util.Abort(_('empty revision set'))
return repo[l[-1]]