Fix scaling if wrong attached window size is returned

Some drivers may return wrong size from wl_egl_window_get_attached_size
and can therefore ignore wl_egl_window_resize calls. This patch
introduces a new env variable QT_WAYLAND_DISABLE_RESIZECHECK to skip
the size check and to force resizing of egl window on create and resize
events.

Task-number: QTBUG-70079
Change-Id: I9be97480088c63ae0a6dc3d1d1e026b0683a627e
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/hardwareintegration/client/wayland-egl/qwaylandeglwindow.cpp b/src/hardwareintegration/client/wayland-egl/qwaylandeglwindow.cpp
index f10a7469a..24dadff4d 100644
--- a/src/hardwareintegration/client/wayland-egl/qwaylandeglwindow.cpp
+++ b/src/hardwareintegration/client/wayland-egl/qwaylandeglwindow.cpp
@@ -126,8 +126,12 @@ void QWaylandEglWindow::updateSurface(bool create)
     } else {
         if (m_waylandEglWindow) {
             int current_width, current_height;
-            wl_egl_window_get_attached_size(m_waylandEglWindow,&current_width,&current_height);
-            if (current_width != sizeWithMargins.width() || current_height != sizeWithMargins.height()) {
+            static bool disableResizeCheck = qgetenv("QT_WAYLAND_DISABLE_RESIZECHECK").toInt();
+
+            if (!disableResizeCheck) {
+                wl_egl_window_get_attached_size(m_waylandEglWindow, &current_width, &current_height);
+            }
+            if (disableResizeCheck || (current_width != sizeWithMargins.width() || current_height != sizeWithMargins.height())) {
                 wl_egl_window_resize(m_waylandEglWindow, sizeWithMargins.width(), sizeWithMargins.height(), mOffset.x(), mOffset.y());
                 mOffset = QPoint();