cmd/gc: reject methods on non-locals, even if symbol exists

Fixes issue 5089.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/7767044

1 files changed, 15 insertions, 0 deletions

diff --git a/test/fixedbugs/issue5089.go b/test/fixedbugs/issue5089.go
new file mode 100644
index 000000000..14d6bde98
--- /dev/null
+++ b/test/fixedbugs/issue5089.go
@@ -0,0 +1,15 @@
+// errorcheck
+
+// Copyright 2013 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.
+
+// issue 5089: gc allows methods on non-locals if symbol already exists
+
+package p
+
+import "bufio"
+
+func (b *bufio.Reader) Buffered() int { // ERROR "non-local"
+	return -1
+}