From 200f6b31f3225b5ab33652bec69fc6fce278dfbc Mon Sep 17 00:00:00 2001
From: kkapsner <github@mail.kkapsner.de>
Date: Fri, 29 Mar 2024 16:37:07 +0100
Subject: [PATCH] Do not use proxy for Function.prototype.toString

Fixes #685
---
 lib/extension.js      | 18 ++++++++----------
 releaseNotes.txt      |  1 +
 test/detectionTest.js | 10 ++++++++++
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/lib/extension.js b/lib/extension.js
index ac41b13ac..d4c92c3f1 100644
--- a/lib/extension.js
+++ b/lib/extension.js
@@ -144,20 +144,18 @@
 	const changedToStrings = new WeakMap();
 	scope.createProxyFunction = function createProxyFunction(window, original, replacement){
 		if (!changedToStrings.get(window)){
-			changedToStrings.set(window, true);
 			const functionPrototype = scope.getWrapped(window).Function.prototype;
-			const toString = functionPrototype.toString;
+			const originalToString = functionPrototype.toString;
+			changedToStrings.set(window, originalToString);
+			const alteredToString = scope.exportFunctionWithName(function toString(){
+				return proxies.get(this) || originalToString.call(this);
+			}, window, "toString");
+			proxies.set(alteredToString, originalToString.call(originalToString));
 			scope.changeProperty(window, "toString", {
 				object: functionPrototype,
 				name: "toString",
 				type: "value",
-				changed: scope.createProxyFunction(
-					window,
-					toString,
-					function(){
-						return proxies.get(this) || toString.call(this);
-					}
-				)
+				changed: alteredToString
 			});
 		}
 		const handler = scope.getWrapped(window).Object.create(null);
@@ -177,7 +175,7 @@
 			}
 		}, window, "");
 		const proxy = new window.Proxy(original, handler);
-		proxies.set(proxy, original.toString());
+		proxies.set(proxy, changedToStrings.get(window).call(original));
 		return scope.getWrapped(proxy);
 	};
 	
diff --git a/releaseNotes.txt b/releaseNotes.txt
index fc73cb8d3..0553a114f 100644
--- a/releaseNotes.txt
+++ b/releaseNotes.txt
@@ -1,6 +1,7 @@
 Version 1.10:
 	changes:
 		- added eBay and facebook.com to the convenience preset
+		- do not use proxy for Function.prototype.toString (causes weird problems sometimes)
 	
 	new features:
 		- added setting showPresetsOnInstallation to be able to not show the presets page upon installation
diff --git a/test/detectionTest.js b/test/detectionTest.js
index 4a9758f8e..411ee5e3e 100644
--- a/test/detectionTest.js
+++ b/test/detectionTest.js
@@ -181,6 +181,16 @@ addTest("toString modified", function(log){
 			configurable: true
 		},
 		log
+	) | checkPropertyDescriptor(
+		Function.prototype,
+		"toString",
+		{
+			value: function toString(){},
+			writable: true,
+			enumerable: false,
+			configurable: true
+		},
+		log
 	);
 });
 addTest("function name", function(log){