1 files changed, 48 insertions, 0 deletions
diff --git a/test/gcstring.go b/test/gcstring.go
new file mode 100644
index 000000000..627a42645
--- /dev/null
+++ b/test/gcstring.go
@@ -0,0 +1,48 @@
+// run
+
+// Copyright 2014 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.
+
+// Test that s[len(s):] - which can point past the end of the allocated block -
+// does not confuse the garbage collector.
+
+package main
+
+import (
+	"runtime"
+	"time"
+)
+
+type T struct {
+	ptr **int
+	pad [120]byte
+}
+
+var things []interface{}
+
+func main() {
+	setup()
+	runtime.GC()
+	runtime.GC()
+	time.Sleep(10*time.Millisecond)
+	runtime.GC()
+	runtime.GC()
+	time.Sleep(10*time.Millisecond)
+}
+
+func setup() {
+	var Ts []interface{}
+	buf := make([]byte, 128)
+	
+	for i := 0; i < 10000; i++ {
+		s := string(buf)
+		t := &T{ptr: new(*int)}
+		runtime.SetFinalizer(t.ptr, func(**int) { panic("*int freed too early") })
+		Ts = append(Ts, t)
+		things = append(things, s[len(s):])
+	}
+	
+	things = append(things, Ts...)
+}
+