[PATCH] Optimize diff-tree -[CM] --stdin

[git.git] / diffcore-rename.c

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 6389ded..035d4eb 100644 (file)
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -99,8 +99,11 @@ static int is_exact_match(struct diff_filespec *src, struct diff_filespec *dst)
        if (src->sha1_valid && dst->sha1_valid &&
            !memcmp(src->sha1, dst->sha1, 20))
                return 1;
-       if (diff_populate_filespec(src) || diff_populate_filespec(dst))
-               /* this is an error but will be caught downstream */
+       if (diff_populate_filespec(src, 1) || diff_populate_filespec(dst, 1))
+               return 0;
+       if (src->size != dst->size)
+               return 0;
+       if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
                return 0;
        if (src->size == dst->size &&
            !memcmp(src->data, dst->data, src->size))
@@ -125,9 +128,11 @@ static int estimate_similarity(struct diff_filespec *src,
         * dst, and then some edit has been applied to dst.
         *
         * Compare them and return how similar they are, representing
-        * the score as an integer between 0 and 10000, except
-        * where they match exactly it is considered better than anything
-        * else.
+        * the score as an integer between 0 and MAX_SCORE.
+        *
+        * When there is an exact match, it is considered a better
+        * match than anything else; the destination does not even
+        * call into this function in that case.
         */
        void *delta;
        unsigned long delta_size, base_size;
@@ -147,6 +152,7 @@ static int estimate_similarity(struct diff_filespec *src,
        /* We would not consider edits that change the file size so
         * drastically.  delta_size must be smaller than
         * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
+        *
         * Note that base_size == 0 case is handled here already
         * and the final score computation below would not have a
         * divide-by-zero issue.
@@ -154,6 +160,9 @@ static int estimate_similarity(struct diff_filespec *src,
        if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
                return 0;
 
+       if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
+               return 0; /* error but caught downstream */
+
        delta = diff_delta(src->data, src->size,
                           dst->data, dst->size,
                           &delta_size);