reftable/stack: handle allocation failures in stack_compact_range()

Handle allocation failures in `stack_compact_range()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

reftable/stack.c

@@ -1131,6 +1131,11 @@ static int stack_compact_range(struct reftable_stack *st,
 	 * from the point of view of the newer process.
 	 */
 	REFTABLE_CALLOC_ARRAY(table_locks, last - first + 1);
+	if (!table_locks) {
+		err = REFTABLE_OUT_OF_MEMORY_ERROR;
+		goto done;
+	}
+
 	for (i = last + 1; i > first; i--) {
 		stack_filename(&table_name, st, reader_name(st->readers[i - 1]));
 
@@ -1312,8 +1317,18 @@ static int stack_compact_range(struct reftable_stack *st,
 		 * thus have to allocate `readers_len + 1` many entries.
 		 */
 		REFTABLE_CALLOC_ARRAY(names, st->merged->readers_len + 1);
-		for (size_t i = 0; i < st->merged->readers_len; i++)
-			names[i] = xstrdup(st->readers[i]->name);
+		if (!names) {
+			err = REFTABLE_OUT_OF_MEMORY_ERROR;
+			goto done;
+		}
+
+		for (size_t i = 0; i < st->merged->readers_len; i++) {
+			names[i] = reftable_strdup(st->readers[i]->name);
+			if (!names[i]) {
+				err = REFTABLE_OUT_OF_MEMORY_ERROR;
+				goto done;
+			}
+		}
 		first_to_replace = first;
 		last_to_replace = last;
 	}