diff --git a/combine-diff.c b/combine-diff.c
index f6b624dc28..33d0ed7097 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -1185,7 +1185,8 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	result_file.ptr = result;
 	result_file.size = result_size;
 
-	/* Even p_lno[cnt+1] is valid -- that is for the end line number
+	/*
+	 * Even p_lno[cnt+1] is valid -- that is for the end line number
 	 * for deletion hunk at the end.
 	 */
 	CALLOC_ARRAY(sline[0].p_lno, st_mult(st_add(cnt, 2), num_parent));
@@ -1220,7 +1221,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	}
 	free(result);
 
-	for (lno = 0; lno < cnt; lno++) {
+	for (lno = 0; lno < cnt + 2; lno++) {
 		if (sline[lno].lost) {
 			struct lline *ll = sline[lno].lost;
 			while (ll) {
diff --git a/t/t4038-diff-combined.sh b/t/t4038-diff-combined.sh
index 2ce26e585c..00190802d8 100755
--- a/t/t4038-diff-combined.sh
+++ b/t/t4038-diff-combined.sh
@@ -5,6 +5,7 @@ test_description='combined diff'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-diff.sh