}
return 0;
}
+
+const char *find_descendant_ref(const char *dirname,
+ const struct string_list *extras,
+ const struct string_list *skip)
+{
+ int pos;
+
+ if (!extras)
+ return NULL;
+
+ /*
+ * Look at the place where dirname would be inserted into
+ * extras. If there is an entry at that position that starts
+ * with dirname (remember, dirname includes the trailing
+ * slash) and is not in skip, then we have a conflict.
+ */
+ for (pos = string_list_find_insert_index(extras, dirname, 0);
+ pos < extras->nr; pos++) {
+ const char *extra_refname = extras->items[pos].string;
+
+ if (!starts_with(extra_refname, dirname))
+ break;
+
+ if (!skip || !string_list_has_string(skip, extra_refname))
+ return extra_refname;
+ }
+ return NULL;
+}
+
+int rename_ref_available(const char *oldname, const char *newname)
+{
+ struct string_list skip = STRING_LIST_INIT_NODUP;
+ struct strbuf err = STRBUF_INIT;
+ int ret;
+
+ string_list_insert(&skip, oldname);
+ ret = !verify_refname_available(newname, NULL, &skip, &err);
+ if (!ret)
+ error("%s", err.buf);
+
+ string_list_clear(&skip, 0);
+ strbuf_release(&err);
+ return ret;
+}