reftable/writer: handle allocation failures in writer_index_hash()

Handle allocation errors in `writer_index_hash()`. Adjust its only
caller in `reftable_writer_add_ref()` accordingly.

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

Author: pks-t

reftable/writer.c

@@ -186,18 +186,22 @@ static int obj_index_tree_node_compare(const void *a, const void *b)
 			  &((const struct obj_index_tree_node *)b)->hash);
 }
 
-static void writer_index_hash(struct reftable_writer *w, struct strbuf *hash)
+static int writer_index_hash(struct reftable_writer *w, struct strbuf *hash)
 {
 	uint64_t off = w->next;
-
 	struct obj_index_tree_node want = { .hash = *hash };
+	struct obj_index_tree_node *key;
+	struct tree_node *node;
 
-	struct tree_node *node = tree_search(&want, &w->obj_index_tree,
-					     &obj_index_tree_node_compare, 0);
-	struct obj_index_tree_node *key = NULL;
+	node = tree_search(&want, &w->obj_index_tree,
+			   &obj_index_tree_node_compare, 0);
 	if (!node) {
 		struct obj_index_tree_node empty = OBJ_INDEX_TREE_NODE_INIT;
-		key = reftable_malloc(sizeof(struct obj_index_tree_node));
+
+		key = reftable_malloc(sizeof(*key));
+		if (!key)
+			return REFTABLE_OUT_OF_MEMORY_ERROR;
+
 		*key = empty;
 
 		strbuf_reset(&key->hash);
@@ -208,12 +212,15 @@ static void writer_index_hash(struct reftable_writer *w, struct strbuf *hash)
 		key = node->key;
 	}
 
-	if (key->offset_len > 0 && key->offsets[key->offset_len - 1] == off) {
-		return;
-	}
+	if (key->offset_len > 0 && key->offsets[key->offset_len - 1] == off)
+		return 0;
 
 	REFTABLE_ALLOC_GROW(key->offsets, key->offset_len + 1, key->offset_cap);
+	if (!key->offsets)
+		return REFTABLE_OUT_OF_MEMORY_ERROR;
 	key->offsets[key->offset_len++] = off;
+
+	return 0;
 }
 
 static int writer_add_record(struct reftable_writer *w,
@@ -284,36 +291,44 @@ int reftable_writer_add_ref(struct reftable_writer *w,
 			.ref = *ref
 		},
 	};
-	int err = 0;
+	struct strbuf buf = STRBUF_INIT;
+	int err;
 
-	if (!ref->refname)
-		return REFTABLE_API_ERROR;
-	if (ref->update_index < w->min_update_index ||
+	if (!ref->refname ||
+	    ref->update_index < w->min_update_index ||
 	    ref->update_index > w->max_update_index)
 		return REFTABLE_API_ERROR;
 
 	rec.u.ref.update_index -= w->min_update_index;
 
 	err = writer_add_record(w, &rec);
 	if (err < 0)
-		return err;
+		goto out;
 
 	if (!w->opts.skip_index_objects && reftable_ref_record_val1(ref)) {
-		struct strbuf h = STRBUF_INIT;
-		strbuf_add(&h, (char *)reftable_ref_record_val1(ref),
+		strbuf_add(&buf, (char *)reftable_ref_record_val1(ref),
 			   hash_size(w->opts.hash_id));
-		writer_index_hash(w, &h);
-		strbuf_release(&h);
+
+		err = writer_index_hash(w, &buf);
+		if (err < 0)
+			goto out;
 	}
 
 	if (!w->opts.skip_index_objects && reftable_ref_record_val2(ref)) {
-		struct strbuf h = STRBUF_INIT;
-		strbuf_add(&h, reftable_ref_record_val2(ref),
+		strbuf_reset(&buf);
+		strbuf_add(&buf, reftable_ref_record_val2(ref),
 			   hash_size(w->opts.hash_id));
-		writer_index_hash(w, &h);
-		strbuf_release(&h);
+
+		err = writer_index_hash(w, &buf);
+		if (err < 0)
+			goto out;
 	}
-	return 0;
+
+	err = 0;
+
+out:
+	strbuf_release(&buf);
+	return err;
 }
 
 int reftable_writer_add_refs(struct reftable_writer *w,