send-pack: fix inconsistent porcelain output

The porcelain output of a failed `git-push` command is inconsistent for
different protocols.  For example, the following `git-push` command
may fail due to the failure of the `pre-receive` hook.

    git push --porcelain origin HEAD:refs/heads/master

For SSH protocol, the porcelain output does not end with a "Done"
message:

	To <URL/of/upstream.git>
	!  HEAD:refs/heads/master  [remote rejected] (pre-receive hook declined)

While for HTTP protocol, the porcelain output does end with a "Done"
message:

	To <URL/of/upstream.git>
	!  HEAD:refs/heads/master  [remote rejected] (pre-receive hook declined)
	Done

The following code at the end of function `send_pack()` indicates that
`send_pack()` should not return an error if some references are rejected
in porcelain mode.

    int send_pack(...)
        ... ...

        if (args->porcelain)
            return 0;

        for (ref = remote_refs; ref; ref = ref->next) {
            switch (ref->status) {
            case REF_STATUS_NONE:
            case REF_STATUS_UPTODATE:
            case REF_STATUS_OK:
                break;
            default:
                return -1;
            }
        }
        return 0;
    }

So if atomic push failed, must check the porcelain mode before return
an error.  And `receive_status()` should not return an error for a
failed updated reference, because `send_pack()` will check them instead.

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

send-pack.c

@@ -190,10 +190,8 @@ static int receive_status(struct packet_reader *reader, struct ref *refs)
 
 		if (reader->line[0] == 'o' && reader->line[1] == 'k')
 			hint->status = REF_STATUS_OK;
-		else {
+		else
 			hint->status = REF_STATUS_REMOTE_REJECT;
-			ret = -1;
-		}
 		hint->remote_status = xstrdup_or_null(msg);
 		/* start our next search from the next ref */
 		hint = hint->next;
@@ -489,7 +487,8 @@ int send_pack(struct send_pack_args *args,
 			if (use_atomic) {
 				strbuf_release(&req_buf);
 				strbuf_release(&cap_buf);
-				return atomic_push_failure(args, remote_refs, ref);
+				atomic_push_failure(args, remote_refs, ref);
+				return args->porcelain ? 0 : -1;
 			}
 			/* else fallthrough */
 		default:

t/t5504-fetch-receive-strict.sh

@@ -65,6 +65,7 @@ test_expect_success 'fetch with transfer.fsckobjects' '
 cat >exp <<EOF
 To dst
 !	refs/heads/master:refs/heads/test	[remote rejected] (missing necessary objects)
+Done
 EOF
 
 test_expect_success 'push without strict' '

t/t5516-fetch-push.sh

@@ -1066,6 +1066,7 @@ test_expect_success 'push --porcelain rejected' '
 
 	echo >.git/foo  "To testrepo"  &&
 	echo >>.git/foo "!	refs/heads/master:refs/heads/master	[remote rejected] (branch is currently checked out)" &&
+	echo >>.git/foo "Done" &&
 
 	test_must_fail git push >.git/bar --porcelain  testrepo refs/heads/master:refs/heads/master &&
 	test_cmp .git/foo .git/bar

t/t5548-push-porcelain.sh

@@ -0,0 +1,280 @@
+#!/bin/sh
+#
+# Copyright (c) 2020 Jiang Xin
+#
+test_description='Test git push porcelain output'
+
+. ./test-lib.sh
+
+# Create commits in <repo> and assign each commit's oid to shell variables
+# given in the arguments (A, B, and C). E.g.:
+#
+#     create_commits_in <repo> A B C
+#
+# NOTE: Never calling this function from a subshell since variable
+# assignments will disappear when subshell exits.
+create_commits_in () {
+	repo="$1" &&
+	if ! parent=$(git -C "$repo" rev-parse HEAD^{} --)
+	then
+		parent=
+	fi &&
+	T=$(git -C "$repo" write-tree) &&
+	shift &&
+	while test $# -gt 0
+	do
+		name=$1 &&
+		test_tick &&
+		if test -z "$parent"
+		then
+			oid=$(echo $name | git -C "$repo" commit-tree $T)
+		else
+			oid=$(echo $name | git -C "$repo" commit-tree -p $parent $T)
+		fi &&
+		eval $name=$oid &&
+		parent=$oid &&
+		shift ||
+		return 1
+	done &&
+	git -C "$repo" update-ref refs/heads/master $oid
+}
+
+# Format the output of git-push, git-show-ref and other commands to make a
+# user-friendly and stable text.  We can easily prepare the expect text
+# without having to worry about future changes of the commit ID and spaces
+# of the output.
+make_user_friendly_and_stable_output () {
+	sed \
+		-e "s/  *\$//" \
+		-e "s/   */ /g" \
+		-e "s/	/    /g" \
+		-e "s/$A/<COMMIT-A>/g" \
+		-e "s/$B/<COMMIT-B>/g" \
+		-e "s/$ZERO_OID/<ZERO-OID>/g" \
+		-e "s/$(echo $A | cut -c1-7)[0-9a-f]*/<OID-A>/g" \
+		-e "s/$(echo $B | cut -c1-7)[0-9a-f]*/<OID-B>/g" \
+		-e "s#To $URL_PREFIX/upstream.git#To <URL/of/upstream.git>#"
+}
+
+setup_upstream_and_workbench () {
+	# Upstream  after setup : master(B)  foo(A)  bar(A)  baz(A)
+	# Workbench after setup : master(A)
+	test_expect_success "setup upstream repository and workbench" '
+		rm -rf upstream.git workbench &&
+		git init --bare upstream.git &&
+		git init workbench &&
+		create_commits_in workbench A B &&
+		(
+			cd workbench &&
+			# Try to make a stable fixed width for abbreviated commit ID,
+			# this fixed-width oid will be replaced with "<OID>".
+			git config core.abbrev 7 &&
+			git remote add origin ../upstream.git &&
+			git update-ref refs/heads/master $A &&
+			git push origin \
+				$B:refs/heads/master \
+				$A:refs/heads/foo \
+				$A:refs/heads/bar \
+				$A:refs/heads/baz
+		) &&
+		git -C "workbench" config advice.pushUpdateRejected false &&
+		upstream=upstream.git
+	'
+}
+
+run_git_push_porcelain_output_test() {
+	case $1 in
+	http)
+		PROTOCOL="HTTP protocol"
+		URL_PREFIX="http://.*"
+		;;
+	file)
+		PROTOCOL="builtin protocol"
+		URL_PREFIX="\.\."
+		;;
+	esac
+
+	# Refs of upstream : master(B)  foo(A)  bar(A)  baz(A)
+	# Refs of workbench: master(A)                  baz(A)  next(A)
+	# git-push         : master(A)  NULL    (B)     baz(A)  next(A)
+	test_expect_success "porcelain output of successful git-push ($PROTOCOL)" '
+		(
+			cd workbench &&
+			git update-ref refs/heads/master $A &&
+			git update-ref refs/heads/baz $A &&
+			git update-ref refs/heads/next $A &&
+			git push --porcelain --force origin \
+				master \
+				:refs/heads/foo \
+				$B:bar \
+				baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/baz:refs/heads/baz    [up to date]
+		     <COMMIT-B>:refs/heads/bar    <OID-A>..<OID-B>
+		-    :refs/heads/foo    [deleted]
+		+    refs/heads/master:refs/heads/master    <OID-B>...<OID-A> (forced update)
+		*    refs/heads/next:refs/heads/next    [new branch]
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$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
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+
+	# Refs of upstream : master(A)  bar(B)  baz(A)  next(A)
+	# Refs of workbench: master(B)  bar(A)  baz(A)  next(A)
+	# git-push         : master(B)  bar(A)  NULL    next(A)
+	test_expect_success "atomic push failed ($PROTOCOL)" '
+		(
+			cd workbench &&
+			git update-ref refs/heads/master $B &&
+			git update-ref refs/heads/bar $A &&
+			test_must_fail git push --atomic --porcelain origin \
+				master \
+				bar \
+				:baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		!    refs/heads/bar:refs/heads/bar    [rejected] (non-fast-forward)
+		!    (delete):refs/heads/baz    [rejected] (atomic push failed)
+		!    refs/heads/master:refs/heads/master    [rejected] (atomic push failed)
+		!    refs/heads/next:refs/heads/next    [rejected] (atomic push failed)
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$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
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+
+	test_expect_success "prepare pre-receive hook ($PROTOCOL)" '
+		write_script "$upstream/hooks/pre-receive" <<-EOF
+		exit 1
+		EOF
+	'
+
+	# Refs of upstream : master(A)  bar(B)  baz(A)  next(A)
+	# Refs of workbench: master(B)  bar(A)  baz(A)  next(A)
+	# git-push         : master(B)  bar(A)  NULL    next(A)
+	test_expect_success "pre-receive hook declined ($PROTOCOL)" '
+		(
+			cd workbench &&
+			git update-ref refs/heads/master $B &&
+			git update-ref refs/heads/bar $A &&
+			test_must_fail git push --porcelain --force origin \
+				master \
+				bar \
+				:baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/next:refs/heads/next    [up to date]
+		!    refs/heads/bar:refs/heads/bar    [remote rejected] (pre-receive hook declined)
+		!    :refs/heads/baz    [remote rejected] (pre-receive hook declined)
+		!    refs/heads/master:refs/heads/master    [remote rejected] (pre-receive hook declined)
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$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
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+
+	test_expect_success "remove pre-receive hook ($PROTOCOL)" '
+		rm "$upstream/hooks/pre-receive"
+	'
+
+	# Refs of upstream : master(A)  bar(B)  baz(A)  next(A)
+	# Refs of workbench: master(B)  bar(A)  baz(A)  next(A)
+	# git-push         : master(B)  bar(A)  NULL    next(A)
+	test_expect_success "non-fastforward push ($PROTOCOL)" '
+		(
+			cd workbench &&
+			test_must_fail git push --porcelain origin \
+				master \
+				bar \
+				:baz \
+				next
+		) >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		To <URL/of/upstream.git>
+		=    refs/heads/next:refs/heads/next    [up to date]
+		-    :refs/heads/baz    [deleted]
+		     refs/heads/master:refs/heads/master    <OID-A>..<OID-B>
+		!    refs/heads/bar:refs/heads/bar    [rejected] (non-fast-forward)
+		Done
+		EOF
+		test_cmp expect actual &&
+
+		git -C "$upstream" show-ref >out &&
+		make_user_friendly_and_stable_output <out >actual &&
+		cat >expect <<-EOF &&
+		<COMMIT-B> refs/heads/bar
+		<COMMIT-B> refs/heads/master
+		<COMMIT-A> refs/heads/next
+		EOF
+		test_cmp expect actual
+	'
+}
+
+# Initialize the upstream repository and local workbench.
+setup_upstream_and_workbench
+
+# Run git-push porcelain test on builtin protocol
+run_git_push_porcelain_output_test file
+
+ROOT_PATH="$PWD"
+. "$TEST_DIRECTORY"/lib-gpg.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+. "$TEST_DIRECTORY"/lib-terminal.sh
+start_httpd
+
+# Re-initialize the upstream repository and local workbench.
+setup_upstream_and_workbench
+
+test_expect_success "setup for http" '
+	git -C upstream.git config http.receivepack true &&
+	upstream="$HTTPD_DOCUMENT_ROOT_PATH/upstream.git" &&
+	mv upstream.git "$upstream" &&
+
+	git -C workbench remote set-url origin $HTTPD_URL/smart/upstream.git
+'
+
+setup_askpass_helper
+
+# Run git-push porcelain test on HTTP protocol
+run_git_push_porcelain_output_test http
+
+test_done

transport.c

@@ -715,7 +715,15 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 
 	close(data->fd[1]);
 	close(data->fd[0]);
-	ret |= finish_connect(data->conn);
+	/*
+	 * Atomic push may abort the connection early and close the pipe,
+	 * which may cause an error for `finish_connect()`. Ignore this error
+	 * for atomic git-push.
+	 */
+	if (ret || args.atomic)
+		finish_connect(data->conn);
+	else
+		ret = finish_connect(data->conn);
 	data->conn = NULL;
 	data->got_remote_heads = 0;