From f85303065c2868aa639351ff59055903c2ff1e25 Mon Sep 17 00:00:00 2001
From: kkapsner <github@mail.kkapsner.de>
Date: Wed, 22 Feb 2017 17:46:17 +0100
Subject: [PATCH] Only interfecpt constructors that are present.

Fixes #108.
---
 lib/intercept.js | 95 +++++++++++++++++++++++++-----------------------
 1 file changed, 49 insertions(+), 46 deletions(-)

diff --git a/lib/intercept.js b/lib/intercept.js
index 8eccb8a..dc3b929 100644
--- a/lib/intercept.js
+++ b/lib/intercept.js
@@ -41,56 +41,59 @@
 				var changedFunction = changedFunctions[name];
 				if (changedFunction.getStatus(undefined, siteStatus).active){
 					(Array.isArray(changedFunction.object)? changedFunction.object: [changedFunction.object]).forEach(function(object){
-						var original = window.wrappedJSObject[object].prototype[name];
-					
-						Object.defineProperty(
-							window.wrappedJSObject[object].prototype,
-							name,
-							{
-								enumerable: true,
-								configureable: false,
-								get: function(){
-									var url = getURL(window);
-									if (!url){
-										return undef;
-									}
-									var error = new Error();
-									if (checkStack(error.stack)){
-										return original;
-									}
-									var funcStatus = changedFunction.getStatus(this, siteStatus);
-									
-									if (funcStatus.active){
-										if (funcStatus.mode === "ask"){
-											funcStatus.mode = ask({window: window, type: changedFunction.type, canvas: this, errorStack: error.stack});
+						var constructor = window.wrappedJSObject[object];
+						if (constructor){
+							var original = constructor.prototype[name];
+						
+							Object.defineProperty(
+								constructor.prototype,
+								name,
+								{
+									enumerable: true,
+									configureable: false,
+									get: function(){
+										var url = getURL(window);
+										if (!url){
+											return undef;
 										}
-										switch (funcStatus.mode){
-											case "allow":
-												return original;
-											case "fake":
-												setRandomSupplyByType(prefs("rng"));
-												var fake = changedFunction.fakeGenerator(prefs, function(messageId){
-													notify({url, errorStack: error.stack, messageId});
-												}, original);
-												switch (fake){
-													case true:
-														return original;
-													case false:
-														return undef;
-													default:
-														return exportFunction(fake, window.wrappedJSObject);
-												}
-											//case "block":
-											default:
-												return undef;
+										var error = new Error();
+										if (checkStack(error.stack)){
+											return original;
+										}
+										var funcStatus = changedFunction.getStatus(this, siteStatus);
+										
+										if (funcStatus.active){
+											if (funcStatus.mode === "ask"){
+												funcStatus.mode = ask({window: window, type: changedFunction.type, canvas: this, errorStack: error.stack});
+											}
+											switch (funcStatus.mode){
+												case "allow":
+													return original;
+												case "fake":
+													setRandomSupplyByType(prefs("rng"));
+													var fake = changedFunction.fakeGenerator(prefs, function(messageId){
+														notify({url, errorStack: error.stack, messageId});
+													}, original);
+													switch (fake){
+														case true:
+															return original;
+														case false:
+															return undef;
+														default:
+															return exportFunction(fake, window.wrappedJSObject);
+													}
+												//case "block":
+												default:
+													return undef;
+											}
+										}
+										else {
+											return original;
 										}
-									}
-									else {
-										return original;
 									}
 								}
-							}
-						);
+							);
+						}
 					});
 				}
 			});