The `cnt` variable tracks the number of lines in a patch diff. It can
happen though that there are no newlines, in which case we'd still end
up allocating our array of `sline`s. In fact, we always allocate it with
`cnt + 2` entries. But when we loop through the array to clear it at the
end of this function we only loop until `lno < cnt`, and thus we may not
end up releasing whatever the two extra `sline`s contain.

Plug this memory leak.

Signed-off-by: Patrick Steinhardt <redacted>
---
 combine-diff.c           | 2 +-
 t/t4038-diff-combined.sh | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/combine-diff.c b/combine-diff.c
index f6b624dc288..3c6d9507fec 100644
--- a/combine-diff.c
+++ b/combine-diff.c

@@ -1220,7 +1220,7 @@ 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 2ce26e585c9..00190802d83 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
 

-- 
2.47.0.dirty