unpack-trees: do not muck with attributes when we are not checking out

diff --git a/diff.c b/diff.c
index 699ae6aca38147a6137cc28bcc1022e70f71db60..3ac71686ebef3d3f9c8b0b72adf612e9535031a5 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -62,6 +62,15 @@ static int parse_diff_color_slot(const char *var, int ofs)
        die("bad config variable '%s'", var);
 }
 
+static int git_config_rename(const char *var, const char *value)
+{
+       if (!value)
+               return DIFF_DETECT_RENAME;
+       if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
+               return  DIFF_DETECT_COPY;
+       return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
+}
+
 /*
  * These are to give UI layer defaults.
  * The core-level commands such as git-diff-files should
@@ -75,13 +84,7 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                return 0;
        }
        if (!strcmp(var, "diff.renames")) {
-               if (!value)
-                       diff_detect_rename_default = DIFF_DETECT_RENAME;
-               else if (!strcasecmp(value, "copies") ||
-                        !strcasecmp(value, "copy"))
-                       diff_detect_rename_default = DIFF_DETECT_COPY;
-               else if (git_config_bool(var,value))
-                       diff_detect_rename_default = DIFF_DETECT_RENAME;
+               diff_detect_rename_default = git_config_rename(var, value);
                return 0;
        }
        if (!strcmp(var, "diff.autorefreshindex")) {
@@ -1757,7 +1760,8 @@ 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
@@ -1797,6 +1801,13 @@ 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.
         */