refs: implement simple transactions for the packed-refs file

diff --git a/transport-helper.c b/transport-helper.c
index 2f5ac3fbeefd65c61c9e9c89f97896f9dfac89c5..06c08a1786391e7a04fa566af0cf42c659ed8aa9 100644 (file)
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -809,6 +809,11 @@ static int push_refs_with_export(struct transport *transport,
        if (!data->refspecs)
                die("remote-helper doesn't support push; refspec needed");
 
+       if (flags & TRANSPORT_PUSH_DRY_RUN) {
+               if (set_helper_option(transport, "dry-run", "true") != 0)
+                       die("helper %s does not support dry-run", data->name);
+       }
+
        helper = get_helper(transport);
 
        write_constant(helper->in, "export\n");
@@ -830,8 +835,14 @@ static int push_refs_with_export(struct transport *transport,
                }
                free(private);
 
-               if (ref->peer_ref)
+               if (ref->deletion)
+                       die("remote-helpers do not support ref deletion");
+
+               if (ref->peer_ref) {
+                       if (strcmp(ref->peer_ref->name, ref->name))
+                               die("remote-helpers do not support old:new syntax");
                        string_list_append(&revlist_args, ref->peer_ref->name);
+               }
        }
 
        if (get_exporter(transport, &exporter, &revlist_args))