receive-pack: extension for server-side report

Each command for the "proc-receive" hook may point to a pseudo-reference
and always has a zero-old as its old-oid.  But the "proc-receive" hook
may update an alternate reference and the reference may exist already
(has a non-zero old-oid).  And we may want certain commands to bypass
the "proc-receive" hook and let "receive-pack" handle them.

In order to report proper reference name, old-oid, and let certain
commands fall through, an extensible reporting method for "proc-receive"
and "receive-pack" is introduced.

The "proc-receive" hook can report its results in the following format:

    # OK, run this command successfully.
    PKT-LINE(<old-oid> <new-oid> <ref> ok)

    # NO, I reject it.
    PKT-LINE(<old-oid> <new-oid> <ref> ng <reason>)

    # Fall through, let "receive-pack" to execute it.
    PKT-LINE(<old-oid> <new-oid> <ref> ft)

    # OK, but has an alternate reference.  The alternate reference name
    # and other status are given in key=value pairs after the null
    # character.
    PKT-LINE(<old-oid> <new-oid> <ref> ok\0ref=refs/pull/123/head
             forced-update)

The reporting function for "receive-pack" is also extended using a
backward compatible way by adding key-value pairs after an null
character, like:

    # OK, run this command successfully with optional extended-status.
    ok <reference>\0ref=refs/pull/123/head old-oid=...

    # NO, I reject it.
    ng <reference> <error message>

This commit only includes changes on the server side, so we can make
a compatible test on old version of a Git client.

Suggested-by: Junio C Hamano <[email protected]>
Signed-off-by: Jiang Xin <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jiangxin

builtin/receive-pack.c

@@ -328,6 +328,7 @@ static void write_head_info(void)
 struct command {
 	struct command *next;
 	const char *error_string;
+	const char *extended_status;
 	unsigned int skip_update:1,
 		     did_not_exist:1,
 		     run_proc_receive:2;
@@ -850,6 +851,7 @@ static int read_proc_receive_report(struct packet_reader *reader,
 {
 	struct command *cmd;
 	struct command *hint = NULL;
+	struct strbuf extended_status = STRBUF_INIT;
 	int code = 0;
 
 	for (;;) {
@@ -858,9 +860,11 @@ static int read_proc_receive_report(struct packet_reader *reader,
 		const char *p;
 		char *status;
 		char *msg = NULL;
+		int len;
 
 		if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 			break;
+		len = strlen(reader->line);
 		if (parse_oid_hex(reader->line, &old_oid, &p) ||
 		    *p++ != ' ' ||
 		    parse_oid_hex(p, &new_oid, &p) ||
@@ -912,16 +916,34 @@ static int read_proc_receive_report(struct packet_reader *reader,
 			else
 				hint->error_string = "failed";
 			code = -1;
+		} else if (!strcmp("ft", status)) {
+			/* Reset "run_proc_receive" field, and continue to run in "receive-pack" */
+			hint->run_proc_receive = 0;
 		} else if (strcmp("ok", status)) {
 			strbuf_addf(errmsg, "proc-receive has bad status '%s' for '%s'\n",
 				    status, reader->line);
 			code = -1;
 			/* Skip marking it as RUN_PROC_RECEIVE_RETURNED */
 			continue;
 		}
-		oidcpy(&hint->old_oid, &old_oid);
-		oidcpy(&hint->new_oid, &new_oid);
-		hint->run_proc_receive |= RUN_PROC_RECEIVE_RETURNED;
+		if (reader->pktlen > len)
+			strbuf_addstr(&extended_status, (char *)reader->line + len + 1);
+		if (oidcmp(&hint->old_oid, &old_oid)) {
+			oidcpy(&hint->old_oid, &old_oid);
+			strbuf_addf(&extended_status, "%sold-oid=%s",
+				    extended_status.len > 0 ? " ": "",
+				    oid_to_hex(&old_oid));
+		}
+		if (oidcmp(&hint->new_oid, &new_oid)) {
+			oidcpy(&hint->new_oid, &new_oid);
+			strbuf_addf(&extended_status, "%snew-oid=%s",
+				    extended_status.len > 0 ? " ": "",
+				    oid_to_hex(&new_oid));
+		}
+		if (extended_status.len > 0)
+			hint->extended_status = strbuf_detach(&extended_status, NULL);
+		if (hint->run_proc_receive)
+			hint->run_proc_receive |= RUN_PROC_RECEIVE_RETURNED;
 	}
 
 	for (cmd = commands; cmd; cmd = cmd->next)
@@ -2179,12 +2201,23 @@ static void report(struct command *commands, const char *unpack_status)
 	packet_buf_write(&buf, "unpack %s\n",
 			 unpack_status ? unpack_status : "ok");
 	for (cmd = commands; cmd; cmd = cmd->next) {
-		if (!cmd->error_string)
-			packet_buf_write(&buf, "ok %s\n",
-					 cmd->ref_name);
-		else
-			packet_buf_write(&buf, "ng %s %s\n",
-					 cmd->ref_name, cmd->error_string);
+		if (!cmd->error_string) {
+			if (cmd->extended_status)
+				packet_buf_write(&buf, "ok %s%c%s\n",
+						 cmd->ref_name, '\0',
+						 cmd->extended_status);
+			else
+				packet_buf_write(&buf, "ok %s\n",
+						 cmd->ref_name);
+		} else {
+			if (cmd->extended_status)
+				packet_buf_write(&buf, "ng %s %s%c%s\n",
+						 cmd->ref_name, cmd->error_string,
+						 '\0', cmd->extended_status);
+			else
+				packet_buf_write(&buf, "ng %s %s\n",
+						 cmd->ref_name, cmd->error_string);
+		}
 	}
 	packet_buf_flush(&buf);
 

t/helper/test-proc-receive.c

@@ -159,8 +159,18 @@ int cmd__proc_receive(int argc, const char **argv)
 	}
 
 	if (returns.nr)
-		for_each_string_list_item(item, &returns)
-			packet_write_fmt(1, "%s\n", item->string);
+		for_each_string_list_item(item, &returns) {
+			char *p;
+
+			p = strstr(item->string, "\\0");
+			if (p) {
+				*p = '\0';
+				p += 2;
+				packet_write_fmt(1, "%s%c%s\n", item->string, '\0', p);
+			} else {
+				packet_write_fmt(1, "%s\n", item->string);
+			}
+		}
 	packet_flush(1);
 	sigchain_pop(SIGPIPE);
 

t/t5411/common-test-cases.sh

@@ -640,8 +640,8 @@ test_expect_success "setup proc-receive hook" '
 
 	test-tool proc-receive -v \
 		-r "$ZERO_OID $A refs/review/a/b/c/topic ok" \
-		-r "$ZERO_OID $A refs/for/next/topic ok" \
-		-r "$B $A refs/for/master/topic ok"
+		-r "$ZERO_OID $A refs/for/next/topic ok\0ref=refs/pull/123/head" \
+		-r "$B $A refs/for/master/topic ok\0ref=refs/pull/124/head forced-update"
 	EOF
 	chmod a+x "$upstream/hooks/proc-receive"
 '
@@ -666,8 +666,8 @@ test_expect_success "report update of all special refs" '
 	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic
 	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
 	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic ok
-	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/next/topic ok
-	remote: proc-receive> <COMMIT-B> <COMMIT-A> refs/for/master/topic ok
+	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/next/topic ok\0ref=refs/pull/123/head
+	remote: proc-receive> <COMMIT-B> <COMMIT-A> refs/for/master/topic ok\0ref=refs/pull/124/head forced-update
 	remote: # post-receive hook
 	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
 	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/review/a/b/c/topic
@@ -701,9 +701,10 @@ test_expect_success "setup proc-receive hook" '
 
 # Refs of upstream : master(A)
 # Refs of workbench: master(A)  tags/v123
-# git push         :                       bar(A)  baz(A)  refs/for/next/topic(A)  foo(A)  refs/for/master/topic(A)
+# git push         : (B)                   bar(A)  baz(A)  refs/for/next/topic(A)  foo(A)  refs/for/master/topic(A)
 test_expect_success "report mixed refs update" '
 	git -C workbench push origin \
+		$B:refs/heads/master \
 		HEAD:refs/heads/bar \
 		HEAD:refs/heads/baz \
 		HEAD:refs/for/next/topic \
@@ -713,6 +714,7 @@ test_expect_success "report mixed refs update" '
 	make_user_friendly_and_stable_output <out >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
+	remote: pre-receive< <COMMIT-A> <COMMIT-B> refs/heads/master
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/bar
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/baz
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
@@ -724,12 +726,14 @@ test_expect_success "report mixed refs update" '
 	remote: proc-receive> <ZERO-OID> <COMMIT-A> refs/for/next/topic ok
 	remote: proc-receive> <COMMIT-A> <COMMIT-B> refs/for/master/topic ok
 	remote: # post-receive hook
+	remote: post-receive< <COMMIT-A> <COMMIT-B> refs/heads/master
 	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/heads/bar
 	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/heads/baz
 	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
 	remote: post-receive< <ZERO-OID> <COMMIT-A> refs/heads/foo
 	remote: post-receive< <COMMIT-A> <COMMIT-B> refs/for/master/topic
 	To <URL/of/upstream.git>
+	 <OID-A>..<OID-B> <COMMIT-B> -> master
 	 * [new branch] HEAD -> bar
 	 * [new branch] HEAD -> baz
 	 * [new reference] HEAD -> refs/for/next/topic
@@ -743,6 +747,80 @@ test_expect_success "report mixed refs update" '
 	<COMMIT-A> refs/heads/bar
 	<COMMIT-A> refs/heads/baz
 	<COMMIT-A> refs/heads/foo
+	<COMMIT-B> refs/heads/master
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success "config receive.procReceiveRefs for all refs" '
+	git -C "$upstream" config --add receive.procReceiveRefs refs
+'
+
+test_expect_success "setup proc-receive hook" '
+	cat >"$upstream/hooks/proc-receive" <<-EOF &&
+	#!/bin/sh
+
+	printf >&2 "# proc-receive hook\n"
+
+	test-tool proc-receive -v \
+		-r "$B $A refs/heads/master ft" \
+		-r "$A $ZERO_OID refs/heads/foo ft" \
+		-r "$A $B refs/heads/bar ft" \
+		-r "$A $B refs/for/master/topic ok\0ref=refs/pull/123/head" \
+		-r "$B $A refs/for/next/topic ok\0ref=refs/pull/124/head forced-update"
+	EOF
+	chmod a+x "$upstream/hooks/proc-receive"
+'
+
+# Refs of upstream : master(B)             foo(A)  bar(A))  baz(A)
+# Refs of workbench: master(A)  tags/v123
+# git push -f      : master(A)             (NULL)  (B)              refs/for/master/topic(A)  refs/for/next/topic(A)
+test_expect_success "report test: fallthrough" '
+	git -C workbench push -f origin \
+		HEAD:refs/heads/master \
+		:refs/heads/foo \
+		$B:refs/heads/bar \
+		HEAD:refs/for/master/topic \
+		HEAD:refs/for/next/topic \
+		>out 2>&1 &&
+	make_user_friendly_and_stable_output <out >actual &&
+	cat >expect <<-EOF &&
+	remote: # pre-receive hook
+	remote: pre-receive< <COMMIT-A> <COMMIT-B> refs/heads/bar
+	remote: pre-receive< <COMMIT-A> <ZERO-OID> refs/heads/foo
+	remote: pre-receive< <COMMIT-B> <COMMIT-A> refs/heads/master
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: # proc-receive hook
+	remote: proc-receive< <COMMIT-A> <COMMIT-B> refs/heads/bar
+	remote: proc-receive< <COMMIT-A> <ZERO-OID> refs/heads/foo
+	remote: proc-receive< <COMMIT-B> <COMMIT-A> refs/heads/master
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/master/topic
+	remote: proc-receive< <ZERO-OID> <COMMIT-A> refs/for/next/topic
+	remote: proc-receive> <COMMIT-B> <COMMIT-A> refs/heads/master ft
+	remote: proc-receive> <COMMIT-A> <ZERO-OID> refs/heads/foo ft
+	remote: proc-receive> <COMMIT-A> <COMMIT-B> refs/heads/bar ft
+	remote: proc-receive> <COMMIT-A> <COMMIT-B> refs/for/master/topic ok\0ref=refs/pull/123/head
+	remote: proc-receive> <COMMIT-B> <COMMIT-A> refs/for/next/topic ok\0ref=refs/pull/124/head forced-update
+	remote: # post-receive hook
+	remote: post-receive< <COMMIT-A> <COMMIT-B> refs/heads/bar
+	remote: post-receive< <COMMIT-A> <ZERO-OID> refs/heads/foo
+	remote: post-receive< <COMMIT-B> <COMMIT-A> refs/heads/master
+	remote: post-receive< <COMMIT-A> <COMMIT-B> refs/for/master/topic
+	remote: post-receive< <COMMIT-B> <COMMIT-A> refs/for/next/topic
+	To <URL/of/upstream.git>
+	 <OID-A>..<OID-B> <COMMIT-B> -> bar
+	 - [deleted] foo
+	 + <OID-B>...<OID-A> HEAD -> master (forced update)
+	 * [new reference] HEAD -> refs/for/master/topic
+	 * [new reference] HEAD -> refs/for/next/topic
+	EOF
+	test_cmp expect actual &&
+	git -C "$upstream" show-ref >out &&
+	make_user_friendly_and_stable_output <out >actual &&
+	cat >expect <<-EOF &&
+	<COMMIT-B> refs/heads/bar
+	<COMMIT-A> refs/heads/baz
 	<COMMIT-A> refs/heads/master
 	EOF
 	test_cmp expect actual