1 files changed, 41 insertions, 0 deletions
diff --git a/test/fixedbugs/issue15277.go b/test/fixedbugs/issue15277.go
new file mode 100644
index 0000000..d22a305
--- /dev/null
+++ b/test/fixedbugs/issue15277.go
@@ -0,0 +1,41 @@
+// run
+
+//go:build amd64
+
+// Copyright 2016 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.
+
+package main
+
+import "runtime"
+
+type big [10 << 20]byte
+
+func f(x *big, start int64) {
+	if delta := inuse() - start; delta < 9<<20 {
+		println("after alloc: expected delta at least 9MB, got: ", delta)
+	}
+	runtime.KeepAlive(x)
+	x = nil
+	if delta := inuse() - start; delta > 1<<20 {
+		println("after drop: expected delta below 1MB, got: ", delta)
+	}
+	x = new(big)
+	if delta := inuse() - start; delta < 9<<20 {
+		println("second alloc: expected delta at least 9MB, got: ", delta)
+	}
+	runtime.KeepAlive(x)
+}
+
+func main() {
+	x := inuse()
+	f(new(big), x)
+}
+
+func inuse() int64 {
+	runtime.GC()
+	var st runtime.MemStats
+	runtime.ReadMemStats(&st)
+	return int64(st.Alloc)
+}