diffcore-rename.c: add locate_rename_src()

Just like rename destination table can be queried without adding a
new entry, add locate_rename_src() that can be used for querying by
splitting register_rename_src() into two (i.e. find existing one and
optionally add new, and then adding information on the new entry).

Signed-off-by: Junio C Hamano <[email protected]>

Author: gitster

diffcore-rename.c

@@ -60,11 +60,10 @@ static struct diff_rename_src {
 } *rename_src;
 static int rename_src_nr, rename_src_alloc;
 
-static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
+static struct diff_rename_src *locate_rename_src(struct diff_filespec *one,
+						 int insert_ok)
 {
 	int first, last;
-	struct diff_filespec *one = p->one;
-	unsigned short score = p->score;
 
 	first = 0;
 	last = rename_src_nr;
@@ -81,6 +80,9 @@ static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
 		first = next+1;
 	}
 
+	if (!insert_ok)
+		return NULL;
+
 	/* insert to make it at "first" */
 	if (rename_src_alloc <= rename_src_nr) {
 		rename_src_alloc = alloc_nr(rename_src_alloc);
@@ -91,11 +93,21 @@ static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
 	if (first < rename_src_nr)
 		memmove(rename_src + first + 1, rename_src + first,
 			(rename_src_nr - first - 1) * sizeof(*rename_src));
-	rename_src[first].p = p;
-	rename_src[first].score = score;
 	return &(rename_src[first]);
 }
 
+static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
+{
+	struct diff_filespec *one = p->one;
+	struct diff_rename_src *src;
+
+	src = locate_rename_src(one, 1);
+
+	src->p = p;
+	src->score = p->score;
+	return src;
+}
+
 static int basename_same(struct diff_filespec *src, struct diff_filespec *dst)
 {
 	int src_len = strlen(src->path), dst_len = strlen(dst->path);