[PATCH] diff: mode bits fixes

The core GIT repository has trees that record regular file mode
in 0664 instead of normalized 0644 pattern.  Comparing such a
tree with another tree that records the same file in 0644
pattern without content changes with git-diff-tree causes it to
feed otherwise unmodified pairs to the diff_change() routine,
which triggers a sanity check routine and barfs.  This patch
fixes the problem, along with the fix to another caller that
uses unnormalized mode bits to call diff_change() routine in a
similar way.

Without this patch, you will see "fatal error" from diff-tree
when you run git-deltafy-script on the core GIT repository
itself.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/diff-files.c b/diff-files.c
index f3a79e5..3b05497 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -88,7 +88,7 @@
 
 	for (i = 0; i < entries; i++) {
 		struct stat st;
-		unsigned int oldmode, mode;
+		unsigned int oldmode;
 		struct cache_entry *ce = active_cache[i];
 		int changed;
 
@@ -116,10 +116,8 @@
 			continue;
 
 		oldmode = ntohl(ce->ce_mode);
-		mode = (S_ISLNK(st.st_mode) ? S_IFLNK :
-			S_IFREG | ce_permissions(st.st_mode));
-
-		show_modified(oldmode, mode, ce->sha1, null_sha1,
+		show_modified(oldmode, DIFF_FILE_CANON_MODE(st.st_mode),
+			      ce->sha1, null_sha1,
 			      ce->name);
 	}
 	diffcore_std((1 < argc) ? argv + 1 : NULL,