Improve trusted-prevent-dom-bypass scriptlet

gorhill · gorhill · commit 68a256bdde5d · 2025-03-25T12:12:00.000-04:00
diff --git a/src/js/resources/scriptlets.js b/src/js/resources/scriptlets.js
@@ -2686,7 +2686,16 @@ function trustedPreventDomBypass(
                     }
                 }
                 if ( targetProp !== '' ) {
-                    elem.contentWindow[targetProp] = self[targetProp];
+                    let me = self, it = elem.contentWindow;
+                    let chain = targetProp;
+                    for (;;) {
+                        const pos = chain.indexOf('.');
+                        if ( pos === -1 ) { break; }
+                        const prop = chain.slice(0, pos)
+                        me = me[prop]; it = it[prop];
+                        chain = chain.slice(pos+1);
+                    }
+                    it[chain] = me[chain];
                 } else {
                     Object.defineProperty(elem, 'contentWindow', { value: self });
                 }

Original file line number	Diff line number	Diff line change
`@@ -2686,7 +2686,16 @@ function trustedPreventDomBypass(`
`2686`	`2686`	`}`
`2687`	`2687`	`}`
`2688`	`2688`	`if ( targetProp !== '' ) {`
`2689`		`- elem.contentWindow[targetProp] = self[targetProp];`
	`2689`	`+ let me = self, it = elem.contentWindow;`
	`2690`	`+ let chain = targetProp;`
	`2691`	`+ for (;;) {`
	`2692`	`+ const pos = chain.indexOf('.');`
	`2693`	`+ if ( pos === -1 ) { break; }`
	`2694`	`+ const prop = chain.slice(0, pos)`
	`2695`	`+ me = me[prop]; it = it[prop];`
	`2696`	`+ chain = chain.slice(pos+1);`
	`2697`	`+ }`
	`2698`	`+ it[chain] = me[chain];`
`2690`	`2699`	`} else {`
`2691`	`2700`	`Object.defineProperty(elem, 'contentWindow', { value: self });`
`2692`	`2701`	`}`