New capability "report-status-v2" for git-push

The new introduced "proc-receive" hook may handle a command for a
pseudo-reference with a zero-old as its old-oid, while the hook may
create or update a reference with different name, different new-oid,
and different old-oid (the reference may exist already with a non-zero
old-oid).  Current "report-status" protocol cannot report the status for
such reference rewrite.

Add new capability "report-status-v2" and new report protocol which is
not backward compatible for report of git-push.

If a user pushes to a pseudo-reference "refs/for/master/topic", and
"receive-pack" creates two new references "refs/changes/23/123/1" and
"refs/changes/24/124/1", for client without the knowledge of
"report-status-v2", "receive-pack" will only send "ok/ng" directives in
the report, such as:

    ok ref/for/master/topic

But for client which has the knowledge of "report-status-v2",
"receive-pack" will use "option" directives to report more attributes
for the reference given by the above "ok/ng" directive.

    ok refs/for/master/topic
    option refname refs/changes/23/123/1
    option new-oid <new-oid>
    ok refs/for/master/topic
    option refname refs/changes/24/124/1
    option new-oid <new-oid>

The client will report two new created references to the end user.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 88 insertions, 28 deletions

diff --git a/transport.c b/transport.c
index 26fefd13c1..e146de6c4e 100644
--- a/transport.c
+++ b/transport.c
@@ -461,13 +461,21 @@ void transport_update_tracking_ref(struct remote *remote, struct ref *ref, int v
 
 static void print_ref_status(char flag, const char *summary,
 			     struct ref *to, struct ref *from, const char *msg,
+			     struct ref_push_report *report,
 			     int porcelain, int summary_width)
 {
+	const char *to_name;
+
+	if (report && report->ref_name)
+		to_name = report->ref_name;
+	else
+		to_name = to->name;
+
 	if (porcelain) {
 		if (from)
-			fprintf(stdout, "%c\t%s:%s\t", flag, from->name, to->name);
+			fprintf(stdout, "%c\t%s:%s\t", flag, from->name, to_name);
 		else
-			fprintf(stdout, "%c\t:%s\t", flag, to->name);
+			fprintf(stdout, "%c\t:%s\t", flag, to_name);
 		if (msg)
 			fprintf(stdout, "%s (%s)\n", summary, msg);
 		else
@@ -481,9 +489,11 @@ static void print_ref_status(char flag, const char *summary,
 		fprintf(stderr, " %s%c %-*s%s ", red, flag, summary_width,
 			summary, reset);
 		if (from)
-			fprintf(stderr, "%s -> %s", prettify_refname(from->name), prettify_refname(to->name));
+			fprintf(stderr, "%s -> %s",
+				prettify_refname(from->name),
+				prettify_refname(to_name));
 		else
-			fputs(prettify_refname(to->name), stderr);
+			fputs(prettify_refname(to_name), stderr);
 		if (msg) {
 			fputs(" (", stderr);
 			fputs(msg, stderr);
@@ -493,27 +503,52 @@ static void print_ref_status(char flag, const char *summary,
 	}
 }
 
-static void print_ok_ref_status(struct ref *ref, int porcelain, int summary_width)
+static void print_ok_ref_status(struct ref *ref,
+				struct ref_push_report *report,
+				int porcelain, int summary_width)
 {
+	struct object_id *old_oid;
+	struct object_id *new_oid;
+	const char *ref_name;
+	int forced_update;
+
+	if (report && report->old_oid)
+		old_oid = report->old_oid;
+	else
+		old_oid = &ref->old_oid;
+	if (report && report->new_oid)
+		new_oid = report->new_oid;
+	else
+		new_oid = &ref->new_oid;
+	if (report && report->forced_update)
+		forced_update = report->forced_update;
+	else
+		forced_update = ref->forced_update;
+	if (report && report->ref_name)
+		ref_name = report->ref_name;
+	else
+		ref_name = ref->name;
+
 	if (ref->deletion)
 		print_ref_status('-', "[deleted]", ref, NULL, NULL,
-				 porcelain, summary_width);
-	else if (is_null_oid(&ref->old_oid))
+				 report, porcelain, summary_width);
+	else if (is_null_oid(old_oid))
 		print_ref_status('*',
-				 (starts_with(ref->name, "refs/tags/")
+				 (starts_with(ref_name, "refs/tags/")
 				  ? "[new tag]"
-				  : (starts_with(ref->name, "refs/heads/")
+				  : (starts_with(ref_name, "refs/heads/")
 				     ? "[new branch]"
 				     : "[new reference]")),
-				 ref, ref->peer_ref, NULL, porcelain, summary_width);
+				 ref, ref->peer_ref, NULL,
+				 report, porcelain, summary_width);
 	else {
 		struct strbuf quickref = STRBUF_INIT;
 		char type;
 		const char *msg;
 
-		strbuf_add_unique_abbrev(&quickref, &ref->old_oid,
+		strbuf_add_unique_abbrev(&quickref, old_oid,
 					 DEFAULT_ABBREV);
-		if (ref->forced_update) {
+		if (forced_update) {
 			strbuf_addstr(&quickref, "...");
 			type = '+';
 			msg = "forced update";
@@ -522,16 +557,17 @@ static void print_ok_ref_status(struct ref *ref, int porcelain, int summary_widt
 			type = ' ';
 			msg = NULL;
 		}
-		strbuf_add_unique_abbrev(&quickref, &ref->new_oid,
+		strbuf_add_unique_abbrev(&quickref, new_oid,
 					 DEFAULT_ABBREV);
 
 		print_ref_status(type, quickref.buf, ref, ref->peer_ref, msg,
-				 porcelain, summary_width);
+				 report, porcelain, summary_width);
 		strbuf_release(&quickref);
 	}
 }
 
-static int print_one_push_status(struct ref *ref, const char *dest, int count,
+static int print_one_push_report(struct ref *ref, const char *dest, int count,
+				 struct ref_push_report *report,
 				 int porcelain, int summary_width)
 {
 	if (!count) {
@@ -543,65 +579,89 @@ static int print_one_push_status(struct ref *ref, const char *dest, int count,
 	switch(ref->status) {
 	case REF_STATUS_NONE:
 		print_ref_status('X', "[no match]", ref, NULL, NULL,
-				 porcelain, summary_width);
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_NODELETE:
 		print_ref_status('!', "[rejected]", ref, NULL,
 				 "remote does not support deleting refs",
-				 porcelain, summary_width);
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_UPTODATE:
 		print_ref_status('=', "[up to date]", ref,
-				 ref->peer_ref, NULL, porcelain, summary_width);
+				 ref->peer_ref, NULL,
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_NONFASTFORWARD:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
-				 "non-fast-forward", porcelain, summary_width);
+				 "non-fast-forward",
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_ALREADY_EXISTS:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
-				 "already exists", porcelain, summary_width);
+				 "already exists",
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_FETCH_FIRST:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
-				 "fetch first", porcelain, summary_width);
+				 "fetch first",
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_NEEDS_FORCE:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
-				 "needs force", porcelain, summary_width);
+				 "needs force",
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_STALE:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
-				 "stale info", porcelain, summary_width);
+				 "stale info",
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REJECT_SHALLOW:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
 				 "new shallow roots not allowed",
-				 porcelain, summary_width);
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_REMOTE_REJECT:
 		print_ref_status('!', "[remote rejected]", ref,
 				 ref->deletion ? NULL : ref->peer_ref,
-				 ref->remote_status, porcelain, summary_width);
+				 ref->remote_status,
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_EXPECTING_REPORT:
 		print_ref_status('!', "[remote failure]", ref,
 				 ref->deletion ? NULL : ref->peer_ref,
 				 "remote failed to report status",
-				 porcelain, summary_width);
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_ATOMIC_PUSH_FAILED:
 		print_ref_status('!', "[rejected]", ref, ref->peer_ref,
-				 "atomic push failed", porcelain, summary_width);
+				 "atomic push failed",
+				 report, porcelain, summary_width);
 		break;
 	case REF_STATUS_OK:
-		print_ok_ref_status(ref, porcelain, summary_width);
+		print_ok_ref_status(ref, report, porcelain, summary_width);
 		break;
 	}
 
 	return 1;
 }
 
+static int print_one_push_status(struct ref *ref, const char *dest, int count,
+				 int porcelain, int summary_width)
+{
+	struct ref_push_report *report;
+	int n = 0;
+
+	if (!ref->report)
+		return print_one_push_report(ref, dest, count,
+					     NULL, porcelain, summary_width);
+
+	for (report = ref->report; report; report = report->next)
+		print_one_push_report(ref, dest, count + n++,
+				      report, porcelain, summary_width);
+	return n;
+}
+
 static int measure_abbrev(const struct object_id *oid, int sofar)
 {
 	char hex[GIT_MAX_HEXSZ + 1];