Stop preserving aborted navigation entries

Consider the scenario

  1. user enters url "http://localhost:8000/"

     A new navigation entry is created and committed in the
     NavigationController.

  2. user enters url "http://localhost:8000/download.bin"

     A new navigation entry is created and a download is triggered, but the
     pending navigation entry in the NavigationController is neither committed
     nor discarded (since our WebContentsDelegate's ShouldPreserveAbortedURLs()
     returns true).

  3. user enters url "http://localhost:8000/download.bin"

     At this point the NavigationController will have "http://localhost:8000/"
     as the committed navigation entry and "http://localhost:8000/download.bin"
     as the pending entry. NavigateToPendingEntry will see that the user is
     trying to navigate again to the same URL as the last pending entry and will
     therefore identify this new navigation as a reload.

     However Blink interprets 'reload' to mean reloading the last committed
     entry, i.e. "http://localhost:8000/", and so we end up trying to download
     "http://localhost:8000/" instead of "http://localhost:8000/download.bin" as
     the user might have expected.

The patch removes the ShouldPreserveAbortedURLs override and relies on the
default implementation which always returns false. As a result the pending
navigation entry in step 2 above is discarded once the download has been
triggered and the unexpected behavior in step 3 is no longer triggered.

Removing the override resurrects QTBUG-48995 where, for example, calling
QWebEnginePage::setUrl triggers first a urlChanged signal for the *old* URL. The
patch adds url and title properties to WebContentsDelegateQt so that property
change signals are triggered only if the properties have actually changed. A
consequence of this fix is that the first urlChanged signal is delivered
directly from the setUrl/load method and not asynchronously once the loading
starts (this is also how Chrome's URL bar is updated).

Task-number: QTBUG-63388
Change-Id: Icfa300b165e5e56f1fbc8978a00a237c263df183
Reviewed-by: Peter Varga <pvarga@inf.u-szeged.hu>

3 files changed, 25 insertions, 21 deletions

diff --git a/src/core/web_contents_adapter.cpp b/src/core/web_contents_adapter.cpp
index effd6e340..ed13883c0 100644
--- a/src/core/web_contents_adapter.cpp
+++ b/src/core/web_contents_adapter.cpp
@@ -594,6 +594,8 @@ void WebContentsAdapter::load(const QWebEngineHttpRequest &request)
     }
 
     d->webContents->GetController().LoadURLWithParams(params);
+    // Follow chrome::Navigate and invalidate the URL immediately.
+    d->webContentsDelegate->NavigationStateChanged(d->webContents.get(), content::INVALIDATE_TYPE_URL);
     focusIfNecessary();
 }
 
@@ -635,7 +637,7 @@ void WebContentsAdapter::save(const QString &filePath, int savePageFormat)
 QUrl WebContentsAdapter::activeUrl() const
 {
     Q_D(const WebContentsAdapter);
-    return toQt(d->webContents->GetLastCommittedURL());
+    return d->webContentsDelegate->url();
 }
 
 QUrl WebContentsAdapter::requestedUrl() const
@@ -670,7 +672,7 @@ QUrl WebContentsAdapter::iconUrl() const
 QString WebContentsAdapter::pageTitle() const
 {
     Q_D(const WebContentsAdapter);
-    return toQt(d->webContents->GetTitle());
+    return d->webContentsDelegate->title();
 }
 
 QString WebContentsAdapter::selectedText() const
diff --git a/src/core/web_contents_delegate_qt.cpp b/src/core/web_contents_delegate_qt.cpp
index f35620c86..96c7c4c41 100644
--- a/src/core/web_contents_delegate_qt.cpp
+++ b/src/core/web_contents_delegate_qt.cpp
@@ -131,10 +131,21 @@ content::WebContents *WebContentsDelegateQt::OpenURLFromTab(content::WebContents
 
 void WebContentsDelegateQt::NavigationStateChanged(content::WebContents* source, content::InvalidateTypes changed_flags)
 {
-    if (changed_flags & content::INVALIDATE_TYPE_URL)
-        m_viewClient->urlChanged(toQt(source->GetVisibleURL()));
-    if (changed_flags & content::INVALIDATE_TYPE_TITLE)
-        m_viewClient->titleChanged(toQt(source->GetTitle()));
+    if (changed_flags & content::INVALIDATE_TYPE_URL) {
+        QUrl newUrl = toQt(source->GetVisibleURL());
+        if (m_url != newUrl) {
+            m_url = newUrl;
+            m_viewClient->urlChanged(m_url);
+        }
+    }
+
+    if (changed_flags & content::INVALIDATE_TYPE_TITLE) {
+        QString newTitle = toQt(source->GetTitle());
+        if (m_title != newTitle) {
+            m_title = newTitle;
+            m_viewClient->titleChanged(m_title);
+        }
+    }
 
     // NavigationStateChanged gets called with INVALIDATE_TYPE_TAB by AudioStateProvider::Notify,
     // whenever an audio sound gets played or stopped, this is the only way to actually figure out
@@ -146,20 +157,6 @@ void WebContentsDelegateQt::NavigationStateChanged(content::WebContents* source,
     }
 }
 
-bool WebContentsDelegateQt::ShouldPreserveAbortedURLs(content::WebContents *source)
-{
-    Q_UNUSED(source)
-
-    // Allow failed URLs to stick around in the URL bar, but only when the error-page is enabled.
-    WebEngineSettings *settings = m_viewClient->webEngineSettings();
-    bool isErrorPageEnabled = settings->testAttribute(settings->Attribute::ErrorPageEnabled);
-
-    if (isErrorPageEnabled)
-        return true;
-
-    return false;
-}
-
 void WebContentsDelegateQt::AddNewContents(content::WebContents* source, content::WebContents* new_contents, WindowOpenDisposition disposition, const gfx::Rect& initial_pos, bool user_gesture, bool* was_blocked)
 {
     Q_UNUSED(source)
diff --git a/src/core/web_contents_delegate_qt.h b/src/core/web_contents_delegate_qt.h
index 44fb93093..8440ec053 100644
--- a/src/core/web_contents_delegate_qt.h
+++ b/src/core/web_contents_delegate_qt.h
@@ -97,6 +97,9 @@ public:
     void setLastSearchedString(const QString &s) { m_lastSearchedString = s; }
     int lastReceivedFindReply() const { return m_lastReceivedFindReply; }
 
+    QUrl url() const { return m_url; }
+    QString title() const { return m_title; }
+
     // WebContentsDelegate overrides
     content::WebContents *OpenURLFromTab(content::WebContents *source, const content::OpenURLParams &params) override;
     void NavigationStateChanged(content::WebContents* source, content::InvalidateTypes changed_flags) override;
@@ -119,7 +122,6 @@ public:
     bool IsPopupOrPanel(const content::WebContents *source) const override;
     void UpdateTargetURL(content::WebContents* source, const GURL& url) override;
     void RequestToLockMouse(content::WebContents *web_contents, bool user_gesture, bool last_unlocked_by_target) override;
-    bool ShouldPreserveAbortedURLs(content::WebContents *source) override;
     void ShowValidationMessage(content::WebContents *web_contents, const gfx::Rect &anchor_in_root_view, const base::string16 &main_text, const base::string16 &sub_text) override;
     void HideValidationMessage(content::WebContents *web_contents) override;
     void MoveValidationMessage(content::WebContents *web_contents, const gfx::Rect &anchor_in_root_view) override;
@@ -165,6 +167,9 @@ private:
     QSharedPointer<FilePickerController> m_filePickerController;
     QUrl m_initialTargetUrl;
     int m_lastLoadProgress;
+
+    QUrl m_url;
+    QString m_title;
 };
 
 } // namespace QtWebEngineCore