reftable/stack: handle allocation failures on reload

Handle allocation failures in `reftable_stack_reload_once()`.

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

Author: pks-t

reftable/stack.c

@@ -214,13 +214,13 @@ void reftable_stack_destroy(struct reftable_stack *st)
 }
 
 static struct reftable_reader **stack_copy_readers(struct reftable_stack *st,
-						   int cur_len)
+						   size_t cur_len)
 {
 	struct reftable_reader **cur = reftable_calloc(cur_len, sizeof(*cur));
-	int i = 0;
-	for (i = 0; i < cur_len; i++) {
+	if (!cur)
+		return NULL;
+	for (size_t i = 0; i < cur_len; i++)
 		cur[i] = st->readers[i];
-	}
 	return cur;
 }
 
@@ -229,18 +229,30 @@ static int reftable_stack_reload_once(struct reftable_stack *st,
 				      int reuse_open)
 {
 	size_t cur_len = !st->merged ? 0 : st->merged->readers_len;
-	struct reftable_reader **cur = stack_copy_readers(st, cur_len);
+	struct reftable_reader **cur;
 	struct reftable_reader **reused = NULL;
-	size_t reused_len = 0, reused_alloc = 0;
-	size_t names_len = names_length(names);
-	struct reftable_reader **new_readers =
-		reftable_calloc(names_len, sizeof(*new_readers));
+	struct reftable_reader **new_readers;
+	size_t reused_len = 0, reused_alloc = 0, names_len;
 	size_t new_readers_len = 0;
 	struct reftable_merged_table *new_merged = NULL;
 	struct strbuf table_path = STRBUF_INIT;
 	int err = 0;
 	size_t i;
 
+	cur = stack_copy_readers(st, cur_len);
+	if (!cur) {
+		err = REFTABLE_OUT_OF_MEMORY_ERROR;
+		goto done;
+	}
+
+	names_len = names_length(names);
+
+	new_readers = reftable_calloc(names_len, sizeof(*new_readers));
+	if (!new_readers) {
+		err = REFTABLE_OUT_OF_MEMORY_ERROR;
+		goto done;
+	}
+
 	while (*names) {
 		struct reftable_reader *rd = NULL;
 		const char *name = *names++;
@@ -261,6 +273,10 @@ static int reftable_stack_reload_once(struct reftable_stack *st,
 				 * do by bumping their refcount.
 				 */
 				REFTABLE_ALLOC_GROW(reused, reused_len + 1, reused_alloc);
+				if (!reused) {
+					err = REFTABLE_OUT_OF_MEMORY_ERROR;
+					goto done;
+				}
 				reused[reused_len++] = rd;
 				reftable_reader_incref(rd);
 				break;