X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=diffcore-rename.c;h=dbc85221320ed06e332fab25325020da241bde78;hb=3d89cb4f3f5333d5eb5899352566ad071dbd0d0c;hp=8fb45f0b8706baa6a1190b21d723d0b0d81203c5;hpb=5569bf9bbedd63a00780fc5c110e0cfab3aa97b9;p=git.git

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 8fb45f0b..dbc85221 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -55,12 +55,12 @@ static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
 /* Table of rename/copy src files */
 static struct diff_rename_src {
 	struct diff_filespec *one;
-	unsigned src_stays : 1;
+	unsigned src_path_left : 1;
 } *rename_src;
 static int rename_src_nr, rename_src_alloc;
 
 static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
-						   int src_stays)
+						   int src_path_left)
 {
 	int first, last;
 
@@ -90,7 +90,7 @@ static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
 		memmove(rename_src + first + 1, rename_src + first,
 			(rename_src_nr - first - 1) * sizeof(*rename_src));
 	rename_src[first].one = one;
-	rename_src[first].src_stays = src_stays;
+	rename_src[first].src_path_left = src_path_left;
 	return &(rename_src[first]);
 }
 
@@ -136,6 +136,7 @@ static int estimate_similarity(struct diff_filespec *src,
 	 */
 	void *delta;
 	unsigned long delta_size, base_size, src_copied, literal_added;
+	unsigned long delta_limit;
 	int score;
 
 	/* We deal only with regular files.  Symlink renames are handled
@@ -163,9 +164,13 @@ static int estimate_similarity(struct diff_filespec *src,
 	if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
 		return 0; /* error but caught downstream */
 
+	delta_limit = base_size * (MAX_SCORE-minimum_score) / MAX_SCORE;
 	delta = diff_delta(src->data, src->size,
 			   dst->data, dst->size,
-			   &delta_size);
+			   &delta_size, delta_limit);
+	if (!delta)
+		/* If delta_limit is exceeded, we have too much differences */
+		return 0;
 
 	/* A delta that has a lot of literal additions would have
 	 * big delta_size no matter what else it does.
@@ -215,7 +220,7 @@ static void record_rename_pair(struct diff_queue_struct *renq,
 
 	dp = diff_queue(renq, one, two);
 	dp->score = score;
-	dp->source_stays = rename_src[src_index].src_stays;
+	dp->source_stays = rename_src[src_index].src_path_left;
 	rename_dst[dst_index].pair = dp;
 }
 
@@ -229,6 +234,21 @@ static int score_compare(const void *a_, const void *b_)
 	return b->score - a->score;
 }
 
+static int compute_stays(struct diff_queue_struct *q,
+			 struct diff_filespec *one)
+{
+	int i;
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		if (strcmp(one->path, p->two->path))
+			continue;
+		if (DIFF_PAIR_RENAME(p)) {
+			return 0; /* something else is renamed into this */
+		}
+	}
+	return 1;
+}
+
 void diffcore_rename(int detect_rename, int minimum_score)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
@@ -401,6 +421,23 @@ void diffcore_rename(int detect_rename, int minimum_score)
 	*q = outq;
 	diff_debug_queue("done collapsing", q);
 
+	/* We need to see which rename source really stays here;
+	 * earlier we only checked if the path is left in the result,
+	 * but even if a path remains in the result, if that is coming
+	 * from copying something else on top of it, then the original
+	 * source is lost and does not stay.
+	 */
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		if (DIFF_PAIR_RENAME(p) && p->source_stays) {
+			/* If one appears as the target of a rename-copy,
+			 * then mark p->source_stays = 0; otherwise
+			 * leave it as is.
+			 */
+			p->source_stays = compute_stays(q, p->one);
+		}
+	}
+
 	free(rename_dst);
 	rename_dst = NULL;
 	rename_dst_nr = rename_dst_alloc = 0;