Merge remote-tracking branch 'origin/5.15' into dev

Change-Id: I784e23d7913294225686879c9bd77dafe3580bac

2 files changed, 7 insertions, 0 deletions

diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 23ed80ab5a..adca902c69 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -1394,6 +1394,8 @@ void QXcbWindow::propagateSizeHints()
     }
 
     xcb_icccm_set_wm_normal_hints(xcb_connection(), m_window, &hints);
+
+    m_sizeHintsScaleFactor = QHighDpiScaling::scaleAndOrigin(screen()).factor;
 }
 
 void QXcbWindow::requestActivateWindow()
@@ -1785,6 +1787,9 @@ void QXcbWindow::handleConfigureNotifyEvent(const xcb_configure_notify_event_t *
     // will make the comparison later.
     QWindowSystemInterface::handleWindowScreenChanged(window(), newScreen->screen());
 
+    if (!qFuzzyCompare(QHighDpiScaling::scaleAndOrigin(newScreen).factor, m_sizeHintsScaleFactor))
+        propagateSizeHints();
+
     // Send the synthetic expose event on resize only when the window is shrinked,
     // because the "XCB_GRAVITY_NORTH_WEST" flag doesn't send it automatically.
     if (!m_oldWindowSize.isEmpty()
diff --git a/src/plugins/platforms/xcb/qxcbwindow.h b/src/plugins/platforms/xcb/qxcbwindow.h
index 13b37db028..976a442b11 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.h
+++ b/src/plugins/platforms/xcb/qxcbwindow.h
@@ -278,6 +278,8 @@ protected:
 
     QXcbSyncWindowRequest *m_pendingSyncRequest = nullptr;
     int m_swapInterval = -1;
+
+    qreal m_sizeHintsScaleFactor = 1.0;
 };
 
 class QXcbForeignWindow : public QXcbWindow