[PATCH] Update rename/copy similarity estimator.

[git.git] / diffcore-rename.c

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 34e83da..07782f4 100644 (file)
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -5,6 +5,7 @@
 #include "diff.h"
 #include "diffcore.h"
 #include "delta.h"
+#include "count-delta.h"
 
 /* Table of rename/copy destinations */
 
@@ -158,13 +159,18 @@ static int estimate_similarity(struct diff_filespec *src,
        delta = diff_delta(src->data, src->size,
                           dst->data, dst->size,
                           &delta_size);
-       /*
-        * We currently punt here, but we may later end up parsing the
-        * delta to really assess the extent of damage.  A big consecutive
-        * remove would produce small delta_size that affects quite a
-        * big portion of the file.
+
+       /* A delta that has a lot of literal additions would have
+        * big delta_size no matter what else it does.
         */
+       if (minimum_score < MAX_SCORE * delta_size / base_size)
+               return 0;
+
+       /* Estimate the edit size by interpreting delta. */
+       delta_size = count_delta(delta, delta_size);
        free(delta);
+       if (delta_size == UINT_MAX)
+               return 0;
 
        /*
         * Now we will give some score to it.  100% edit gets 0 points