Merge pull request #29140 from brave/ios-js-pref-fix-1.79.x

[iOS] Reset `javaScriptEnabled` preference correctly between navigations (uplift to 1.79.x)

Author: kjozwiak

chromium_src/ios/web/navigation/crw_wk_navigation_handler.mm

@@ -40,6 +40,20 @@ - (void)webView:(WKWebView*)webView
           // Only ever update it to false
           preferences.allowsContentJavaScript = false;
         }
+
+        if (@available(iOS 18, *)) {
+        } else {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+          // In prior versions of iOS,
+          // `WKWebpagePreferences.allowsContentJavaScript` does not work
+          // correctly in all cases:
+          // https://github.com/brave/brave-ios/issues/8585
+          webView.configuration.preferences.javaScriptEnabled =
+              preferences.allowsContentJavaScript;
+#pragma clang diagnostic pop
+        }
+
         if (policy == WKNavigationActionPolicyAllow) {
           // Check if we want to explicitly block universal links
           bool forceBlockUniversalLinks = brave::ShouldBlockUniversalLinks(

ios/brave-ios/Sources/Web/WebKit/TabWKNavigationHandler.swift

@@ -116,17 +116,13 @@ class TabWKNavigationHandler: NSObject, WKNavigationDelegate {
       if let delegate = tab.delegate,
         delegate.tab(tab, shouldBlockJavaScriptForRequest: navigationAction.request)
       {
-        // Due to a bug in iOS WKWebpagePreferences.allowsContentJavaScript does NOT work!
-        // https://github.com/brave/brave-ios/issues/8585
-        //
-        // However, the deprecated API WKWebViewConfiguration.preferences.javaScriptEnabled DOES work!
-        // Even though `configuration` is @NSCopying, somehow this actually updates the preferences LIVE!!
-        // This follows the same behaviour as Safari
-        //
-        // - Brandon T.
-        //
         preferences.allowsContentJavaScript = false
-        webView.configuration.preferences.javaScriptEnabled = false
+      }
+
+      if #unavailable(iOS 18.0) {
+        // In prior versions of iOS, `WKWebpagePreferences.allowsContentJavaScript` does not work
+        // correctly in all cases: https://github.com/brave/brave-ios/issues/8585
+        webView.configuration.preferences.javaScriptEnabled = preferences.allowsContentJavaScript
       }
 
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