1 files changed, 70 insertions, 0 deletions
diff --git a/test/fixedbugs/issue34723.go b/test/fixedbugs/issue34723.go
new file mode 100644
index 0000000..402d465
--- /dev/null
+++ b/test/fixedbugs/issue34723.go
@@ -0,0 +1,70 @@
+// errorcheck -0 -d=wb
+
+// Copyright 2019 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.
+
+// Make sure we don't introduce write barriers where we
+// don't need them. These cases are writing pointers to
+// globals to zeroed memory.
+
+package main
+
+func f1() []string {
+	return []string{"a"}
+}
+
+func f2() []string {
+	return []string{"a", "b"}
+}
+
+type T struct {
+	a [6]*int
+}
+
+func f3() *T {
+	t := new(T)
+	t.a[0] = &g
+	t.a[1] = &g
+	t.a[2] = &g
+	t.a[3] = &g
+	t.a[4] = &g
+	t.a[5] = &g
+	return t
+}
+
+func f4() *T {
+	t := new(T)
+	t.a[5] = &g
+	t.a[4] = &g
+	t.a[3] = &g
+	t.a[2] = &g
+	t.a[1] = &g
+	t.a[0] = &g
+	return t
+}
+
+func f5() *T {
+	t := new(T)
+	t.a[4] = &g
+	t.a[2] = &g
+	t.a[0] = &g
+	t.a[3] = &g
+	t.a[1] = &g
+	t.a[5] = &g
+	return t
+}
+
+type U struct {
+	a [65]*int
+}
+
+func f6() *U {
+	u := new(U)
+	u.a[63] = &g
+	// This offset is too large: we only track the first 64 pointers for zeroness.
+	u.a[64] = &g // ERROR "write barrier"
+	return u
+}
+
+var g int