From 2642607a58dd832cc494a7e42deb8fa73d64708d Mon Sep 17 00:00:00 2001
From: Robert Krimen <robertkrimen@gmail.com>
Date: Sat, 20 Apr 2013 20:03:34 -0700
Subject: [PATCH] Fix HasInstance to recurse the prototype hierarchy

---
 error_test.go    | 15 +++++++++++++++
 type_function.go | 13 +++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)
 create mode 100644 error_test.go

diff --git a/error_test.go b/error_test.go
new file mode 100644
index 0000000..ab3ca48
--- /dev/null
+++ b/error_test.go
@@ -0,0 +1,15 @@
+package otto
+
+import (
+	. "./terst"
+	"testing"
+)
+
+func TestError_instanceof(t *testing.T) {
+	Terst(t)
+
+	test := runTest()
+	test(`
+        (new TypeError()) instanceof Error
+    `, "true")
+}
diff --git a/type_function.go b/type_function.go
index e9da4cb..9d6ea11 100644
--- a/type_function.go
+++ b/type_function.go
@@ -86,11 +86,16 @@ func (self *_object) HasInstance(of Value) bool {
 	if !prototype.IsObject() {
 		panic(newTypeError())
 	}
-	ofPrototype := of._object().prototype
-	if ofPrototype == nil {
-		return false
+	prototypeObject := prototype._object()
+
+	value := of._object().prototype
+	for value != nil {
+		if value == prototypeObject {
+			return true
+		}
+		value = value.prototype
 	}
-	return ofPrototype == prototype._object()
+	return false
 }
 
 type _functionSignature string