1 files changed, 68 insertions, 0 deletions
diff --git a/test/fixedbugs/issue45851.go b/test/fixedbugs/issue45851.go
new file mode 100644
index 0000000..b137071
--- /dev/null
+++ b/test/fixedbugs/issue45851.go
@@ -0,0 +1,68 @@
+// run
+
+// Copyright 2021 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.
+
+// This tickles a stack-allocation bug when the register ABI is enabled.
+// The original report was from cue, internal/core/adt/equality.go,
+// function equalVertex.
+
+// In the failing case, something bad gets passed to equalTerminal.
+
+package main
+
+import "fmt"
+
+type Kind uint16
+type Flag uint16
+
+const (
+	allKinds Kind = 1
+	TopKind  Kind = (allKinds - 1)
+)
+type Value interface {
+	Kind() Kind
+}
+type Vertex struct {
+	BaseValue Value
+	name string
+}
+func (v *Vertex) Kind() Kind {
+	return TopKind
+}
+
+func main() {
+	vA := &Vertex{name:"vA",}
+	vB := &Vertex{name:"vB",}
+	vX := &Vertex{name:"vX",}
+	vA.BaseValue = vX
+	vB.BaseValue = vX
+	_ = equalVertex(vA, vB, Flag(1))
+}
+
+var foo string
+
+//go:noinline
+func (v *Vertex) IsClosedStruct() bool {
+	return true
+}
+
+func equalVertex(x *Vertex, v Value, flags Flag) bool {
+	y, ok := v.(*Vertex)
+	if !ok {
+		return false
+	}
+	v, ok1 := x.BaseValue.(Value)
+	w, ok2 := y.BaseValue.(Value)
+	if !ok1 && !ok2 {
+		return true // both are struct or list.
+	}
+	return equalTerminal(v, w, flags)
+}
+
+//go:noinline
+func equalTerminal(x Value, y Value, flags Flag) bool {
+	foo = fmt.Sprintf("EQclosed %s %s %d\n", x.(*Vertex).name, y.(*Vertex).name, flags)
+	return true
+}