From 95323c59eaa6ffa8c76450c19a3831c88ecd19e3 Mon Sep 17 00:00:00 2001
From: Nigel Tao <nigeltao@golang.org>
Date: Mon, 18 Jul 2011 15:54:11 +1000
Subject: [PATCH] runtime: fix panic for make(chan [0]byte).

I suspect that this was introduced by
http://code.google.com/p/go/source/detail?r=6e4ee32fffd1

R=r
CC=golang-dev
https://golang.org/cl/4764045
---
 src/pkg/runtime/chan.c |  2 +-
 test/chan/zerosize.go  | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 test/chan/zerosize.go

diff --git a/src/pkg/runtime/chan.c b/src/pkg/runtime/chan.c
index 78f67b817c0..efaceebf5a3 100644
--- a/src/pkg/runtime/chan.c
+++ b/src/pkg/runtime/chan.c
@@ -97,7 +97,7 @@ runtime·makechan_c(Type *elem, int64 hint)
 	int32 n;
 	byte *by;
 
-	if(hint < 0 || (int32)hint != hint || hint > ((uintptr)-1) / elem->size)
+	if(hint < 0 || (int32)hint != hint || (elem->size > 0 && hint > ((uintptr)-1) / elem->size))
 		runtime·panicstring("makechan: size out of range");
 
 	if(elem->alg >= nelem(runtime·algarray)) {
diff --git a/test/chan/zerosize.go b/test/chan/zerosize.go
new file mode 100644
index 00000000000..617c9dab341
--- /dev/null
+++ b/test/chan/zerosize.go
@@ -0,0 +1,16 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Making channels of a zero-sized type should not panic.
+
+package main
+
+func main() {
+	_ = make(chan [0]byte)
+	_ = make(chan [0]byte, 1)
+	_ = make(chan struct{})
+	_ = make(chan struct{}, 1)
+}