diffcore-break: don't divide by zero
When the source file is empty, the calculation of the merge score
results in a division by zero. In the situation:
== preimage == == postimage ==
F (empty file) F (a large file)
E (a new empty file)
it does not make sense to consider F->E as a rename, so it is better not
to break the pre- and post-image of F.
Bail out early in this case to avoid hitting the divide-by-zero. This
causes the merge score to be left at zero.
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/diffcore-break.c b/diffcore-break.c
index 44f8678..1d9e530 100644
--- a/diffcore-break.c
+++ b/diffcore-break.c
@@ -68,6 +68,9 @@
if (max_size < MINIMUM_BREAK_SIZE)
return 0; /* we do not break too small filepair */
+ if (!src->size)
+ return 0; /* we do not let empty files get renamed */
+
if (diffcore_count_changes(src, dst,
&src->cnt_data, &dst->cnt_data,
0,
