+int combine_notes_concatenate(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ char *cur_msg = NULL, *new_msg = NULL, *buf;
+ unsigned long cur_len, new_len, buf_len;
+ enum object_type cur_type, new_type;
+ int ret;
+
+ /* read in both note blob objects */
+ if (!is_null_sha1(new_sha1))
+ new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
+ if (!new_msg || !new_len || new_type != OBJ_BLOB) {
+ free(new_msg);
+ return 0;
+ }
+ if (!is_null_sha1(cur_sha1))
+ cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
+ if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
+ free(cur_msg);
+ free(new_msg);
+ hashcpy(cur_sha1, new_sha1);
+ return 0;
+ }
+
+ /* we will separate the notes by a newline anyway */
+ if (cur_msg[cur_len - 1] == '\n')
+ cur_len--;
+
+ /* concatenate cur_msg and new_msg into buf */
+ buf_len = cur_len + 1 + new_len;
+ buf = (char *) xmalloc(buf_len);
+ memcpy(buf, cur_msg, cur_len);
+ buf[cur_len] = '\n';
+ memcpy(buf + cur_len + 1, new_msg, new_len);
+ free(cur_msg);
+ free(new_msg);
+
+ /* create a new blob object from buf */
+ ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
+ free(buf);
+ return ret;
+}
+
+int combine_notes_overwrite(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ hashcpy(cur_sha1, new_sha1);
+ return 0;
+}
+
+int combine_notes_ignore(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ return 0;
+}
+
+void init_notes(struct notes_tree *t, const char *notes_ref,
+ combine_notes_fn combine_notes, int flags)