keyword: postpone manifest calculation in kwtemplater.overwrite

keyword: postpone manifest calculation in kwtemplater.overwrite

We can check for file existence in the working directory (needed
in case of recording) by simply using the given context and
calculate the manifest only when there are in fact candidates
for expansion/shrinking.

--- a/hgext/keyword.py	Sun Jun 13 23:25:27 2010 +0200
+++ b/hgext/keyword.py	Tue Jun 15 17:15:31 2010 +0200
@@ -191,12 +191,12 @@
 
     def overwrite(self, ctx, candidates, iswctx, expand):
         '''Overwrites selected files expanding/shrinking keywords.'''
-        mf = ctx.manifest()
         if self.record:
-            candidates = [f for f in ctx.files() if f in mf]
+            candidates = [f for f in ctx.files() if f in ctx]
         candidates = [f for f in candidates if self.iskwfile(f, ctx.flags)]
         if candidates:
             self.restrict = True        # do not expand when reading
+            mf = ctx.manifest()
             msg = (expand and _('overwriting %s expanding keywords\n')
                    or _('overwriting %s shrinking keywords\n'))
             for f in candidates: