remote-curl: Fix push status report when all branches fail

The protocol between transport-helper.c and remote-curl requires
remote-curl to always print a blank line after the push command
has run. If the blank line is ommitted, transport-helper kills its
container process (the git push the user started) with exit(128)
and no message indicating a problem, assuming the helper already
printed reasonable error text to the console.

However if the remote rejects all branches with "ng" commands in the
report-status reply, send-pack terminates with non-zero status, and
in turn remote-curl exited with non-zero status before outputting
the blank line after the helper status printed by send-pack. No
error messages reach the user.

This caused users to see the following from git push over HTTP
when the remote side's update hook rejected the branch:

  $ git push http://... master
  Counting objects: 4, done.
  Delta compression using up to 6 threads.
  Compressing objects: 100% (2/2), done.
  Writing objects: 100% (3/3), 301 bytes, done.
  Total 3 (delta 0), reused 0 (delta 0)
  $

Always print a blank line after the send-pack process terminates,
ensuring the helper status report (if it was output) will be
correctly parsed by the calling transport-helper.c. This ensures
the helper doesn't abort before the status report can be shown to
the user.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

remote-curl.c

@@ -797,7 +797,7 @@ static int push(int nr_spec, char **specs)
 static void parse_push(struct strbuf *buf)
 {
 	char **specs = NULL;
-	int alloc_spec = 0, nr_spec = 0, i;
+	int alloc_spec = 0, nr_spec = 0, i, ret;
 
 	do {
 		if (!prefixcmp(buf->buf, "push ")) {
@@ -814,12 +814,13 @@ static void parse_push(struct strbuf *buf)
 			break;
 	} while (1);
 
-	if (push(nr_spec, specs))
-		exit(128); /* error already reported */
-
+	ret = push(nr_spec, specs);
 	printf("\n");
 	fflush(stdout);
 
+	if (ret)
+		exit(128); /* error already reported */
+
  free_specs:
 	for (i = 0; i < nr_spec; i++)
 		free(specs[i]);

t/t5541-http-push.sh

@@ -95,6 +95,32 @@ test_expect_success 'create and delete remote branch' '
 	test_must_fail git show-ref --verify refs/remotes/origin/dev
 '
 
+cat >"$HTTPD_DOCUMENT_ROOT_PATH/test_repo.git/hooks/update" <<EOF
+#!/bin/sh
+exit 1
+EOF
+chmod a+x "$HTTPD_DOCUMENT_ROOT_PATH/test_repo.git/hooks/update"
+
+cat >exp <<EOF
+remote: error: hook declined to update refs/heads/dev2
+To http://127.0.0.1:$LIB_HTTPD_PORT/smart/test_repo.git
+ ! [remote rejected] dev2 -> dev2 (hook declined)
+error: failed to push some refs to 'http://127.0.0.1:5541/smart/test_repo.git'
+EOF
+
+test_expect_success 'rejected update prints status' '
+	cd "$ROOT_PATH"/test_repo_clone &&
+	git checkout -b dev2 &&
+	: >path4 &&
+	git add path4 &&
+	test_tick &&
+	git commit -m dev2 &&
+	test_must_fail git push origin dev2 2>act &&
+	sed -e "/^remote: /s/ *$//" <act >cmp &&
+	test_cmp exp cmp
+'
+rm -f "$HTTPD_DOCUMENT_ROOT_PATH/test_repo.git/hooks/update"
+
 cat >exp <<EOF
 
 GET  /smart/test_repo.git/info/refs?service=git-upload-pack HTTP/1.1 200
@@ -106,6 +132,8 @@ GET  /smart/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
 POST /smart/test_repo.git/git-receive-pack HTTP/1.1 200
 GET  /smart/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
 POST /smart/test_repo.git/git-receive-pack HTTP/1.1 200
+GET  /smart/test_repo.git/info/refs?service=git-receive-pack HTTP/1.1 200
+POST /smart/test_repo.git/git-receive-pack HTTP/1.1 200
 EOF
 test_expect_success 'used receive-pack service' '
 	sed -e "