Merge remote-tracking branch 'origin/5.4.0' into 5.4

Change-Id: If7b9ae7b6f77025c775e6b654837b5f041f1aab9

src/assistant/assistant/assistant_images.qrc

 <RCC>
     <qresource prefix="/qt-project.org/assistant">
-        <file>images/qt-logo.png</file>
         <file>images/assistant-128.png</file>
         <file>images/assistant.png</file>
         <file>images/wrap.png</file>

src/assistant/help/qhelpcontentwidget.cpp

@@ -219,6 +219,11 @@ void QHelpContentProvider::stopCollecting()
         m_abort = true;
         m_mutex.unlock();
         wait();
+        // we need to force-set m_abort to false, because the thread might either have
+        // finished between the isRunning() check and the "m_abort = true" above, or the
+        // isRunning() check might already happen after the "m_abort = false" in the run() method,
+        // either way never resetting m_abort to false from within the run() method
+        m_abort = false;
     }
     qDeleteAll(m_rootItems);
     m_rootItems.clear();