index 416c5aa722afc8d10e4bc910e7b297b3eb0a2760..635fbc9d98995359b045de8a7a8594af2fe0e335 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1649,7 +1649,8 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
struct stat st;
int pos, len;
- /* We do not read the cache ourselves here, because the
+ /*
+ * We do not read the cache ourselves here, because the
* benchmark with my previous version that always reads cache
* shows that it makes things worse for diff-tree comparing
* two linux-2.6 kernel trees in an already checked out work
@@ -1689,6 +1690,13 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
return 0;
+ /*
+ * If ce is marked as "assume unchanged", there is no
+ * guarantee that work tree matches what we are looking for.
+ */
+ if (ce->ce_flags & CE_VALID)
+ return 0;
+
/*
* If ce matches the file in the work tree, we can reuse it.
*/