transport-helper: update remote helper namespace

When pushing, the remote namespace is updated correctly
(e.g. refs/origin/master), but not the remote helper's
(e.g. refs/testgit/origin/master), which currently is only
updated while fetching.

Since the remote namespace is used to tell fast-export which commits
to avoid (because they were already imported/exported), it makes
sense to have them in sync so they don't get generated twice. If the
remote helper was implemented properly, they would be ignored, if
not, they probably would end up repeated.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5801-remote-helpers.sh

@@ -153,6 +153,18 @@ test_expect_success 'push ref with existing object' '
 	compare_refs local dup server dup
 '
 
+test_expect_success 'push update refs' '
+	(cd local &&
+	git checkout -b update master &&
+	echo update >>file &&
+	git commit -a -m update &&
+	git push origin update
+	git rev-parse --verify remotes/origin/update >expect &&
+	git rev-parse --verify testgit/origin/heads/update >actual &&
+	test_cmp expect actual
+	)
+'
+
 test_expect_success 'proper failure checks for fetching' '
 	(GIT_REMOTE_TESTGIT_FAILURE=1 &&
 	export GIT_REMOTE_TESTGIT_FAILURE &&

transport-helper.c

@@ -11,6 +11,7 @@
 #include "thread-utils.h"
 #include "sigchain.h"
 #include "argv-array.h"
+#include "refs.h"
 
 static int debug;
 
@@ -620,7 +621,7 @@ static int fetch(struct transport *transport,
 	return -1;
 }
 
-static void push_update_ref_status(struct strbuf *buf,
+static int push_update_ref_status(struct strbuf *buf,
 				   struct ref **ref,
 				   struct ref *remote_refs)
 {
@@ -686,7 +687,7 @@ static void push_update_ref_status(struct strbuf *buf,
 		*ref = find_ref_by_name(remote_refs, refname);
 	if (!*ref) {
 		warning("helper reported unexpected status of %s", refname);
-		return;
+		return 1;
 	}
 
 	if ((*ref)->status != REF_STATUS_NONE) {
@@ -695,11 +696,12 @@ static void push_update_ref_status(struct strbuf *buf,
 		 * status reported by the remote helper if the latter is 'no match'.
 		 */
 		if (status == REF_STATUS_NONE)
-			return;
+			return 1;
 	}
 
 	(*ref)->status = status;
 	(*ref)->remote_status = msg;
+	return 0;
 }
 
 static void push_update_refs_status(struct helper_data *data,
@@ -708,11 +710,24 @@ static void push_update_refs_status(struct helper_data *data,
 	struct strbuf buf = STRBUF_INIT;
 	struct ref *ref = remote_refs;
 	for (;;) {
+		char *private;
+
 		recvline(data, &buf);
 		if (!buf.len)
 			break;
 
-		push_update_ref_status(&buf, &ref, remote_refs);
+		if (push_update_ref_status(&buf, &ref, remote_refs))
+			continue;
+
+		if (!data->refspecs)
+			continue;
+
+		/* propagate back the update to the remote namespace */
+		private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
+		if (!private)
+			continue;
+		update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
+		free(private);
 	}
 	strbuf_release(&buf);
 }