diff --git a/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.h b/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.h
index c929cc6..1c88447 100644
--- a/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.h
+++ b/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.h
@@ -112,13 +112,13 @@ private:
     QRect m_geometry;
     QRect m_availableGeometry;
     QDpi m_logicalDpi;
-    qreal m_refreshRate = 0;
-    int m_depth = 0;
+    qreal m_refreshRate;
+    int m_depth;
     QString m_name;
     QImage::Format m_format;
     QSizeF m_physicalSize;
     QCocoaCursor *m_cursor;
-    qreal m_devicePixelRatio = 0;
+    qreal m_devicePixelRatio;
 
     CVDisplayLinkRef m_displayLink = nullptr;
     dispatch_source_t m_displayLinkSource = nullptr;
diff --git a/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.mm b/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.mm
index e4dd4cf..a66483c 100644
--- a/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.mm
+++ b/5.13.2/qtbase/src/plugins/platforms/cocoa/qcocoascreen.mm
@@ -471,6 +471,15 @@ void QCocoaScreen::deliverUpdateRequests()
             // it on the main thread yet, because the processing of the update request is taking
             // too long, or because the update request was deferred due to window live resizing.
             qDeferredDebug(screenUpdates) << ", " << framesAheadOfDelivery << " frame(s) ahead";
+
+            // We skip the frame completely if we're live-resizing, to not put any extra
+            // strain on the main thread runloop. Otherwise we assume we should push frames
+            // as fast as possible, and hopefully the callback will be delivered on the
+            // main thread just when the previous finished.
+            if (qt_apple_sharedApplication().keyWindow.inLiveResize) {
+                qDeferredDebug(screenUpdates) << "; waiting for main thread to catch up";
+                return;
+            }
         }
 
         qDeferredDebug(screenUpdates) << "; signaling dispatch source";