Merge branch 'hv/remote-end-hung-up'

When we get disconnected while expecting a response from the remote
side because authentication failed, we issued an error message "The
remote side hung up unexpectedly."

Give hint that it may be a permission problem in the message when we
can reasonably suspect it.

* hv/remote-end-hung-up:
  remove the impression of unexpectedness when access is denied

connect.c

@@ -49,13 +49,25 @@ static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1
 	extra->nr++;
 }
 
+static void die_initial_contact(int got_at_least_one_head)
+{
+	if (got_at_least_one_head)
+		die("The remote end hung up upon initial contact");
+	else
+		die("Could not read from remote repository.\n\n"
+		    "Please make sure you have the correct access rights\n"
+		    "and the repository exists.");
+}
+
 /*
  * Read all the refs from the other end
  */
 struct ref **get_remote_heads(int in, struct ref **list,
 			      unsigned int flags,
 			      struct extra_have_objects *extra_have)
 {
+	int got_at_least_one_head = 0;
+
 	*list = NULL;
 	for (;;) {
 		struct ref *ref;
@@ -64,7 +76,10 @@ struct ref **get_remote_heads(int in, struct ref **list,
 		char *name;
 		int len, name_len;
 
-		len = packet_read_line(in, buffer, sizeof(buffer));
+		len = packet_read(in, buffer, sizeof(buffer));
+		if (len < 0)
+			die_initial_contact(got_at_least_one_head);
+
 		if (!len)
 			break;
 		if (buffer[len-1] == '\n')
@@ -95,6 +110,7 @@ struct ref **get_remote_heads(int in, struct ref **list,
 		hashcpy(ref->old_sha1, old_sha1);
 		*list = ref;
 		list = &ref->next;
+		got_at_least_one_head = 1;
 	}
 	return list;
 }

pkt-line.c

@@ -135,13 +135,19 @@ void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 	strbuf_add(buf, buffer, n);
 }
 
-static void safe_read(int fd, void *buffer, unsigned size)
+static int safe_read(int fd, void *buffer, unsigned size, int return_line_fail)
 {
 	ssize_t ret = read_in_full(fd, buffer, size);
 	if (ret < 0)
 		die_errno("read error");
-	else if (ret < size)
+	else if (ret < size) {
+		if (return_line_fail)
+			return -1;
+
 		die("The remote end hung up unexpectedly");
+	}
+
+	return ret;
 }
 
 static int packet_length(const char *linelen)
@@ -169,12 +175,14 @@ static int packet_length(const char *linelen)
 	return len;
 }
 
-int packet_read_line(int fd, char *buffer, unsigned size)
+static int packet_read_internal(int fd, char *buffer, unsigned size, int return_line_fail)
 {
-	int len;
+	int len, ret;
 	char linelen[4];
 
-	safe_read(fd, linelen, 4);
+	ret = safe_read(fd, linelen, 4, return_line_fail);
+	if (return_line_fail && ret < 0)
+		return ret;
 	len = packet_length(linelen);
 	if (len < 0)
 		die("protocol error: bad line length character: %.4s", linelen);
@@ -185,12 +193,24 @@ int packet_read_line(int fd, char *buffer, unsigned size)
 	len -= 4;
 	if (len >= size)
 		die("protocol error: bad line length %d", len);
-	safe_read(fd, buffer, len);
+	ret = safe_read(fd, buffer, len, return_line_fail);
+	if (return_line_fail && ret < 0)
+		return ret;
 	buffer[len] = 0;
 	packet_trace(buffer, len, 0);
 	return len;
 }
 
+int packet_read(int fd, char *buffer, unsigned size)
+{
+	return packet_read_internal(fd, buffer, size, 1);
+}
+
+int packet_read_line(int fd, char *buffer, unsigned size)
+{
+	return packet_read_internal(fd, buffer, size, 0);
+}
+
 int packet_get_line(struct strbuf *out,
 	char **src_buf, size_t *src_len)
 {

pkt-line.h

@@ -13,6 +13,7 @@ void packet_buf_flush(struct strbuf *buf);
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 
 int packet_read_line(int fd, char *buffer, unsigned size);
+int packet_read(int fd, char *buffer, unsigned size);
 int packet_get_line(struct strbuf *out, char **src_buf, size_t *src_len);
 ssize_t safe_write(int, const void *, ssize_t);
 

t/t5512-ls-remote.sh

@@ -87,17 +87,15 @@ test_expect_success 'use branch.<name>.remote if possible' '
 test_expect_success 'confuses pattern as remote when no remote specified' '
 	cat >exp <<-\EOF &&
 	fatal: '\''refs*master'\'' does not appear to be a git repository
-	fatal: The remote end hung up unexpectedly
+	fatal: Could not read from remote repository.
+
+	Please make sure you have the correct access rights
+	and the repository exists.
 	EOF
 	#
-	# Do not expect "git ls-remote <pattern>" to work; ls-remote, correctly,
-	# confuses <pattern> for <remote>. Although ugly, this behaviour is akin
-	# to the confusion of refspecs for remotes by git-fetch and git-push,
-	# eg:
-	#
-	#   $ git fetch branch
-	#
-
+	# Do not expect "git ls-remote <pattern>" to work; ls-remote needs
+	# <remote> if you want to feed <pattern>, just like you cannot say
+	# fetch <branch>.
 	# We could just as easily have used "master"; the "*" emphasizes its
 	# role as a pattern.
 	test_must_fail git ls-remote refs*master >actual 2>&1 &&