Respect custom QWSI event handler when delivering synchronous events

Fixes: QTBUG-110268
Change-Id: I25195904cfc18d593db1be713b6e899e55eb922f
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 2813e2814e185bf8d2426c5eb3d6b2c243ee72c3)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index 21091f66fa..051fe38a48 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -98,7 +98,12 @@ bool QWindowSystemHelper<QWindowSystemInterface::SynchronousDelivery>::handleEve
     if (QThread::currentThread() == QGuiApplication::instance()->thread()) {
         EventType event(args...);
         // Process the event immediately on the Gui thread and return the accepted state
-        QGuiApplicationPrivate::processWindowSystemEvent(&event);
+        if (QWindowSystemInterfacePrivate::eventHandler) {
+            if (!QWindowSystemInterfacePrivate::eventHandler->sendEvent(&event))
+                return false;
+        } else {
+            QGuiApplicationPrivate::processWindowSystemEvent(&event);
+        }
         return event.eventAccepted;
     } else {
         // Post the event on the Qt main thread queue and flush the queue.