Fix use-after-free in WebContentsAdapter::load

Pass WebContentsAdapter pointer to lambda via QWeakPointer in case the adapter
has been deleted already.

Fixes: QTBUG-76958
Change-Id: I1962ba3dd1794a27e7013a2ad1b729fe7a08c079
Reviewed-by: Allan Sandfeld Jensen <[email protected]>

Author: valdmann

src/core/web_contents_adapter.cpp

@@ -653,19 +653,23 @@ void WebContentsAdapter::load(const QWebEngineHttpRequest &request)
         }
     }
 
-    auto navigate = [](WebContentsAdapter *adapter, const content::NavigationController::LoadURLParams &params) {
+    auto navigate = [](QWeakPointer<WebContentsAdapter> weakAdapter, const content::NavigationController::LoadURLParams &params) {
+        WebContentsAdapter *adapter = weakAdapter.data();
+        if (!adapter)
+            return;
         adapter->webContents()->GetController().LoadURLWithParams(params);
         // Follow chrome::Navigate and invalidate the URL immediately.
         adapter->m_webContentsDelegate->NavigationStateChanged(adapter->webContents(), content::INVALIDATE_TYPE_URL);
         adapter->focusIfNecessary();
     };
 
+    QWeakPointer<WebContentsAdapter> weakThis(sharedFromThis());
     if (resizeNeeded) {
         // Schedule navigation on the event loop.
         content::BrowserThread::PostTask(
-            content::BrowserThread::UI, FROM_HERE, base::BindOnce(navigate, this, std::move(params)));
+            content::BrowserThread::UI, FROM_HERE, base::BindOnce(navigate, std::move(weakThis), std::move(params)));
     } else {
-        navigate(this, params);
+        navigate(std::move(weakThis), params);
     }
 }