Reviewers: golang-dev_googlegroups.com,
Message:
Hello [email protected] (cc: [email protected]),
I'd like you to review this change to
https://go.googlecode.com/hg/
Description:
runtime: fix a panic when growing zero-width-element slices.
Fixes issue 4197.
Please review this at http://codereview.appspot.com/6611056/
Affected files:
M src/pkg/runtime/slice.c
A test/fixedbugs/bug457.go
Index: src/pkg/runtime/slice.c
===================================================================
--- a/src/pkg/runtime/slice.c
+++ b/src/pkg/runtime/slice.c
@@ -114,7 +114,7 @@
cap = old.cap + n;
- if((intgo)cap != cap || cap < old.cap || cap > MaxMem / t->elem->size)
+ if((intgo)cap != cap || cap < old.cap || t->elem->size > 0 && cap >
MaxMem / t->elem->size)
runtime·panicstring("growslice: cap out of range");
growslice1(t, old, cap, &ret);
Index: test/fixedbugs/bug457.go
===================================================================
new file mode 100644
--- /dev/null
+++ b/test/fixedbugs/bug457.go
@@ -0,0 +1,15 @@
+// run
+
+// Copyright 2012 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 4197: growing a slice of zero-width elements
+// panics on a division by zero.
+
+package main
+
+func main() {
+ var x []struct{}
+ x = append(x, struct{}{})
+}
