# HG changeset patch
# User Siddharth Agarwal <sid0@fb.com>
# Date 1363997029 25200
# Node ID a18919de61e5a11747a8856e6acfbaaa457fb479
# Parent  1413ba4102448cebc47e2c97512dc63eb7c87f47
dirstate.walk: fast path none-seen + match-always case for step 3

This case is a common one -- e.g. `hg diff`.

For a repository with 170,000 files, this speeds up perfstatus from 0.95
seconds to 0.88.

diff -r 1413ba410244 -r a18919de61e5 mercurial/dirstate.py
--- a/mercurial/dirstate.py	Fri Mar 22 17:03:00 2013 -0700
+++ b/mercurial/dirstate.py	Fri Mar 22 17:03:49 2013 -0700
@@ -705,7 +705,12 @@
 
         # step 3: report unseen items in the dmap hash
         if not skipstep3 and not exact:
-            visit = sorted([f for f in dmap if f not in results and matchfn(f)])
+            if not results and matchalways:
+                visit = dmap.keys()
+            else:
+                visit = [f for f in dmap if f not in results and matchfn(f)]
+            visit.sort()
+
             if unknown:
                 # unknown == True means we walked the full directory tree above.
                 # So if a file is not seen it was either a) not matching matchfn