MT#61368 add function to merge to bencode buffers

Change-Id: I1c5d28b6e241c60f5c71c7e5f04845a082182778

daemon/bencode.c

@@ -146,6 +146,12 @@ void bencode_buffer_free(bencode_buffer_t *buf) {
 	}
 }
 
+void bencode_buffer_merge(bencode_buffer_t *to, bencode_buffer_t *from) {
+	from->pieces->next = to->pieces;
+	to->pieces = from->pieces;
+	from->pieces = NULL;
+}
+
 static bencode_item_t *__bencode_item_alloc(bencode_buffer_t *buf, size_t payload) {
 	bencode_item_t *ret;
 

include/bencode.h

@@ -69,6 +69,9 @@ void *bencode_buffer_alloc(bencode_buffer_t *, size_t);
  * and all objects created through it become invalid. */
 void bencode_buffer_free(bencode_buffer_t *buf);
 
+// Move all objects from one buffer to another. The `from` buffer will be unusable afterwards.
+void bencode_buffer_merge(bencode_buffer_t *to, bencode_buffer_t *from);
+
 /* Creates a new empty dictionary object. Memory will be allocated from the bencode_buffer_t object.
  * Returns NULL if no memory could be allocated. */
 bencode_item_t *bencode_dictionary(bencode_buffer_t *buf);