[PATCH 2 of 4] icasefs: follow standard cache look up pattern

[FUJIWARA Katsunori]

# HG changeset patch
# User FUJIWARA Katsunori <foozy at lares.dti.ne.jp>
# Date 1324655474 -32400
# Node ID 1dd60426b0611d23db184a8210b56ccbb6c3ea9d
# Parent  c604a3d1969d174f7564bb045d62863995b7dabc
icasefs: follow standard cache look up pattern

diff -r c604a3d1969d -r 1dd60426b061 mercurial/util.py
--- a/mercurial/util.py	Sat Dec 24 00:50:56 2011 +0900
+++ b/mercurial/util.py	Sat Dec 24 00:51:14 2011 +0900
@@ -640,10 +640,9 @@
             result.append(sep)
             continue
 
-        contents = _fspathcache.get(dir, None)
-        if contents is None:
-            contents = os.listdir(dir)
-            _fspathcache[dir] = contents
+        if dir not in _fspathcache:
+            _fspathcache[dir] = os.listdir(dir)
+        contents = _fspathcache[dir]
 
         found = find(part, contents)
         if not found: