reftable/stack: handle allocation failures in auto compaction

Handle allocation failures in `reftable_stack_auto_compact()`.

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

Author: pks-t

reftable/stack.c

@@ -1518,6 +1518,8 @@ static uint64_t *stack_table_sizes_for_compaction(struct reftable_stack *st)
 	uint64_t *sizes;
 
 	REFTABLE_CALLOC_ARRAY(sizes, st->merged->readers_len);
+	if (!sizes)
+		return NULL;
 
 	for (size_t i = 0; i < st->merged->readers_len; i++)
 		sizes[i] = st->readers[i]->size - overhead;
@@ -1527,11 +1529,17 @@ static uint64_t *stack_table_sizes_for_compaction(struct reftable_stack *st)
 
 int reftable_stack_auto_compact(struct reftable_stack *st)
 {
-	uint64_t *sizes = stack_table_sizes_for_compaction(st);
-	struct segment seg =
-		suggest_compaction_segment(sizes, st->merged->readers_len,
-					   st->opts.auto_compaction_factor);
+	struct segment seg;
+	uint64_t *sizes;
+
+	sizes = stack_table_sizes_for_compaction(st);
+	if (!sizes)
+		return REFTABLE_OUT_OF_MEMORY_ERROR;
+
+	seg = suggest_compaction_segment(sizes, st->merged->readers_len,
+					 st->opts.auto_compaction_factor);
 	reftable_free(sizes);
+
 	if (segment_size(&seg) > 0)
 		return stack_compact_range(st, seg.start, seg.end - 1,
 					   NULL, STACK_COMPACT_RANGE_BEST_EFFORT);