Merge branch 'jk/always-allow-large-packets'

"git push" and "git fetch" did not communicate an overlong refname
correctly.

* jk/always-allow-large-packets:
  pkt-line: allow writing of LARGE_PACKET_MAX buffers

Author: gitster

pkt-line.c

@@ -64,44 +64,45 @@ void packet_buf_flush(struct strbuf *buf)
 }
 
 #define hex(a) (hexchar[(a) & 15])
-static char buffer[1000];
-static unsigned format_packet(const char *fmt, va_list args)
+static void format_packet(struct strbuf *out, const char *fmt, va_list args)
 {
 	static char hexchar[] = "0123456789abcdef";
-	unsigned n;
+	size_t orig_len, n;
 
-	n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
-	if (n >= sizeof(buffer)-4)
+	orig_len = out->len;
+	strbuf_addstr(out, "0000");
+	strbuf_vaddf(out, fmt, args);
+	n = out->len - orig_len;
+
+	if (n > LARGE_PACKET_MAX)
 		die("protocol error: impossibly long line");
-	n += 4;
-	buffer[0] = hex(n >> 12);
-	buffer[1] = hex(n >> 8);
-	buffer[2] = hex(n >> 4);
-	buffer[3] = hex(n);
-	packet_trace(buffer+4, n-4, 1);
-	return n;
+
+	out->buf[orig_len + 0] = hex(n >> 12);
+	out->buf[orig_len + 1] = hex(n >> 8);
+	out->buf[orig_len + 2] = hex(n >> 4);
+	out->buf[orig_len + 3] = hex(n);
+	packet_trace(out->buf + orig_len + 4, n - 4, 1);
 }
 
 void packet_write(int fd, const char *fmt, ...)
 {
+	static struct strbuf buf = STRBUF_INIT;
 	va_list args;
-	unsigned n;
 
+	strbuf_reset(&buf);
 	va_start(args, fmt);
-	n = format_packet(fmt, args);
+	format_packet(&buf, fmt, args);
 	va_end(args);
-	write_or_die(fd, buffer, n);
+	write_or_die(fd, buf.buf, buf.len);
 }
 
 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 {
 	va_list args;
-	unsigned n;
 
 	va_start(args, fmt);
-	n = format_packet(fmt, args);
+	format_packet(buf, fmt, args);
 	va_end(args);
-	strbuf_add(buf, buffer, n);
 }
 
 static int get_packet_data(int fd, char **src_buf, size_t *src_size,

t/t5527-fetch-odd-refs.sh

@@ -26,4 +26,37 @@ test_expect_success 'suffix ref is ignored during fetch' '
 	test_cmp expect actual
 '
 
+test_expect_success 'try to create repo with absurdly long refname' '
+	ref240=$_z40/$_z40/$_z40/$_z40/$_z40/$_z40 &&
+	ref1440=$ref240/$ref240/$ref240/$ref240/$ref240/$ref240 &&
+	git init long &&
+	(
+		cd long &&
+		test_commit long &&
+		test_commit master
+	) &&
+	if git -C long update-ref refs/heads/$ref1440 long; then
+		test_set_prereq LONG_REF
+	else
+		echo >&2 "long refs not supported"
+	fi
+'
+
+test_expect_success LONG_REF 'fetch handles extremely long refname' '
+	git fetch long refs/heads/*:refs/remotes/long/* &&
+	cat >expect <<-\EOF &&
+	long
+	master
+	EOF
+	git for-each-ref --format="%(subject)" refs/remotes/long >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success LONG_REF 'push handles extremely long refname' '
+	git push long :refs/heads/$ref1440 &&
+	git -C long for-each-ref --format="%(subject)" refs/heads >actual &&
+	echo master >expect &&
+	test_cmp expect actual
+'
+
 test_done