Show error if web process never connects

App/Browser View/BrowserViewController.swift

@@ -282,6 +282,30 @@ class BrowserViewController: UIViewController, WKNavigationDelegate, WKUIDelegat
     func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
         loadError = nil
         
+        // Check to make sure we have connected to the web content process
+        if !tab.bridge.webContentProcessConnected {
+            // This means we started loading a page but the web content process hasn't loaded, which means
+            // scripts are not getting blocked.
+            
+            // If you're ad-hoc signing this, you'll need to disable library validation:
+            // sudo defaults write /Library/Preferences/com.apple.security.libraryvalidation DisableLibraryValidation -bool YES
+            
+            DispatchQueue.main.async { [unowned self] in
+                // Stop loading now
+                webView.stopLoading()
+                
+                // Show an alert
+                let alert = UIAlertController(title: "Web Process Not Loaded",
+                                              message: "The web content process never contacted the host application",
+                                              preferredStyle: .alert)
+                alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { _ in
+                    alert.dismiss(animated: true, completion: nil)
+                }))
+                
+                present(alert, animated: true, completion: nil)
+            }
+        }
+        
         // Reset tracking this
         tab.allowedScriptOrigins.removeAll()
         tab.blockedScriptOrigins.removeAll()

App/Web Process Bundle Bridge/SBRProcessBundleBridge.h

@@ -32,6 +32,8 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, assign) BOOL allowAllScripts; // default is NO
 @property (nonatomic, assign) BOOL darkModeEnabled;
 
+@property (nonatomic, readonly) BOOL webContentProcessConnected;
+
 - (void)policyDataSourceDidChange;
 - (void)tearDown;
 

App/Web Process Bundle Bridge/SBRProcessBundleBridge.m

@@ -105,6 +105,8 @@
 - (void)webProcessDidConnect
 {
     NSLog(@"SBRProcessBundleBridge: did connect. Saying hello, syncing allowlist");
+    _webContentProcessConnected = YES;
+    
     [_webProcessProxy hello];
     [self policyDataSourceDidChange];
 }