Fix double LoadFinished on URL errors

RenderFrameDeleted was called before DidFinishLoad, which meant
m_loadingErrorFrameList was empty and wouldn't detect the page loaded
was an error page. Instead this patch relies on the chromium error-page
url which we already asserted.

Additonally we delay emitting the loadFinished signal until the error
page is also done loading, since the error-page can be considered part
of the load, and we otherwise have a race condition on toPlainText.

Finally we were not getting error-pages when blocking requests because
we reported them as aborted them instead of blocked.

Change-Id: I945eb838b7f080d4e146f18354e8986e1b88b5cd
Task-number: QTBUG-50752
Reviewed-by: Michael Brüning <michael.bruning@theqtcompany.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/src/webenginewidgets/api/qwebenginepage.cpp b/src/webenginewidgets/api/qwebenginepage.cpp
index b1bf33067..458ddae5f 100644
--- a/src/webenginewidgets/api/qwebenginepage.cpp
+++ b/src/webenginewidgets/api/qwebenginepage.cpp
@@ -200,13 +200,21 @@ void QWebEnginePagePrivate::loadFinished(bool success, const QUrl &url, bool isE
     Q_UNUSED(errorCode);
     Q_UNUSED(errorDescription);
 
-    if (isErrorPage)
+    if (isErrorPage) {
+        Q_ASSERT(settings->testAttribute(QWebEngineSettings::ErrorPageEnabled));
+        Q_ASSERT(success);
+        Q_EMIT q->loadFinished(false);
         return;
+    }
 
     isLoading = false;
     if (success)
         explicitUrl = QUrl();
-    Q_EMIT q->loadFinished(success);
+    // Delay notifying failure until the error-page is done loading.
+    // Error-pages are not loaded on failures due to abort.
+    if (success || errorCode == -3 /* ERR_ABORTED*/ || !settings->testAttribute(QWebEngineSettings::ErrorPageEnabled)) {
+        Q_EMIT q->loadFinished(success);
+    }
     updateNavigationActions();
 }