Fix deadlock when starting a drag

With commit c55a36cb9015cf1eebd49eaa5b1b4f4ec9b28451 in qtbase the
QSimpleDrag code changed in a way that caused a deadlock due to
drawing a window without a role. However, thanks to that we can
now remove that start/cancel hack and simplify the code.

Change-Id: Icba6e7c9c4927855e48fb21632db1a10332c4ffb
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

1 files changed, 1 insertions, 13 deletions

diff --git a/src/client/qwaylanddnd.cpp b/src/client/qwaylanddnd.cpp
index 59f91411f..e195d193a 100644
--- a/src/client/qwaylanddnd.cpp
+++ b/src/client/qwaylanddnd.cpp
@@ -65,21 +65,9 @@ QMimeData * QWaylandDrag::platformDropData()
 
 void QWaylandDrag::startDrag()
 {
-    bool cancel = false;
-    if (!shapedPixmapWindow()) {
-        QBasicDrag::startDrag();
-        // Don't call cancel() here, since that will hide 'shapedPixmapWindow()', and
-        // QWaylandWindow::setVisible(false) will flush the window system queue,
-        // ending up trying to render the window, which doesn't have a role yet,
-        // and so blocking waiting for a frame callback.
-        cancel = true;
-    }
-
+    QBasicDrag::startDrag();
     QWaylandWindow *icon = static_cast<QWaylandWindow *>(shapedPixmapWindow()->handle());
     m_display->currentInputDevice()->dataDevice()->startDrag(drag()->mimeData(), icon);
-    if (cancel)
-        QBasicDrag::cancel();
-    QBasicDrag::startDrag();
 }
 
 void QWaylandDrag::cancel()