diffcore-break: similarity estimator fix.
This is a companion patch to the previous fix to diffcore-rename.
The merging-back process should use a logic similar to what is used
there.
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/diffcore-break.c b/diffcore-break.c
index 0fc2b86..71ad58a 100644
--- a/diffcore-break.c
+++ b/diffcore-break.c
@@ -45,8 +45,8 @@
* The value we return is 1 if we want the pair to be broken,
* or 0 if we do not.
*/
- unsigned long delta_size, base_size, src_copied, literal_added;
- int to_break = 0;
+ unsigned long delta_size, base_size, src_copied, literal_added,
+ src_removed;
*merge_score_p = 0; /* assume no deletion --- "do not break"
* is the default.
@@ -72,33 +72,40 @@
&src_copied, &literal_added))
return 0;
+ /* sanity */
+ if (src->size < src_copied)
+ src_copied = src->size;
+ if (dst->size < literal_added + src_copied) {
+ if (src_copied < dst->size)
+ literal_added = dst->size - src_copied;
+ else
+ literal_added = 0;
+ }
+ src_removed = src->size - src_copied;
+
/* Compute merge-score, which is "how much is removed
* from the source material". The clean-up stage will
* merge the surviving pair together if the score is
* less than the minimum, after rename/copy runs.
*/
- if (src->size <= src_copied)
- ; /* all copied, nothing removed */
- else {
- delta_size = src->size - src_copied;
- *merge_score_p = delta_size * MAX_SCORE / src->size;
- }
-
+ *merge_score_p = src_removed * MAX_SCORE / src->size;
+
/* Extent of damage, which counts both inserts and
* deletes.
*/
- if (src->size + literal_added <= src_copied)
- delta_size = 0; /* avoid wrapping around */
- else
- delta_size = (src->size - src_copied) + literal_added;
-
- /* We break if the edit exceeds the minimum.
- * i.e. (break_score / MAX_SCORE < delta_size / base_size)
- */
- if (break_score * base_size < delta_size * MAX_SCORE)
- to_break = 1;
+ delta_size = src_removed + literal_added;
+ if (delta_size * MAX_SCORE / base_size < break_score)
+ return 0;
- return to_break;
+ /* If you removed a lot without adding new material, that is
+ * not really a rewrite.
+ */
+ if ((src->size * break_score < src_removed * MAX_SCORE) &&
+ (literal_added * 20 < src_removed) &&
+ (literal_added * 20 < src_copied))
+ return 0;
+
+ return 1;
}
void diffcore_break(int break_score)
