runtime: fix correctness test at end of traceback

We were requiring that the defer stack and the panic stack
be completely processed, thinking that if any were left over
the stack scan and the defer stack/panic stack must be out
of sync. It turns out that the panic stack may well have
leftover entries in some situations, and that's okay.

Fixes issue 8132.

LGTM=minux, r
R=golang-codereviews, minux, r
CC=golang-codereviews, iant, khr
https://codereview.appspot.com/100900044

1 files changed, 32 insertions, 0 deletions

diff --git a/test/fixedbugs/issue8132.go b/test/fixedbugs/issue8132.go
new file mode 100644
index 000000000..52f5d39c2
--- /dev/null
+++ b/test/fixedbugs/issue8132.go
@@ -0,0 +1,32 @@
+// 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.
+
+// issue 8132. stack walk handling of panic stack was confused
+// about what was legal.
+
+package main
+
+import "runtime"
+
+var p *int
+
+func main() {
+	func() {
+		defer func() {
+			runtime.GC()
+			recover()
+		}()
+		var x [8192]byte
+		func(x [8192]byte) {
+			defer func() {
+				if err := recover(); err != nil {
+					println(*p)
+				}
+			}()
+			println(*p)
+		}(x)
+	}()
+}