From dd5c9e2d894ca94faaeef7dfc3cc4344a7f62640 Mon Sep 17 00:00:00 2001
From: Michael Weghorn <m.weghorn@posteo.de>
Date: Mon, 20 Feb 2023 14:02:23 +0100
Subject: [PATCH] Convert cursor bitmap to supported format

The 1-bit image formats QImage::Format_Mono and
QImage::Format_MonoLSB used by cursor bitmaps don't have
a corresponding wl_shm_format.

Therefore, convert to a supported image format as necessary
to make such bitmap cursors work on Wayland as well.

Fixes: QTBUG-95434
Change-Id: I402fd870b301ddc01075251b66f2cf7cc1923133
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit 45ec1362f8fcb5ade92f4d2d4985b1c24e78c8ba)

Backport changes: Use Qt::ReturnByValue version for QCursor::mask() and QCursor::bitmap()
---
 src/client/qwaylandcursor.cpp | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/client/qwaylandcursor.cpp b/src/client/qwaylandcursor.cpp
index e4eca9d4e..ba76ba2d0 100644
--- a/src/client/qwaylandcursor.cpp
+++ b/src/client/qwaylandcursor.cpp
@@ -44,6 +44,7 @@
 #include "qwaylandshmbackingstore_p.h"
 
 #include <QtGui/QImageReader>
+#include <QBitmap>
 #include <QDebug>
 
 #include <wayland-cursor.h>
@@ -250,7 +251,27 @@ QWaylandCursor::QWaylandCursor(QWaylandDisplay *display)
 QSharedPointer<QWaylandBuffer> QWaylandCursor::cursorBitmapBuffer(QWaylandDisplay *display, const QCursor *cursor)
 {
     Q_ASSERT(cursor->shape() == Qt::BitmapCursor);
-    const QImage &img = cursor->pixmap().toImage();
+
+    const QBitmap mask = cursor->mask(Qt::ReturnByValue);
+    QImage img;
+    if (cursor->pixmap().isNull())
+        img = cursor->bitmap(Qt::ReturnByValue).toImage();
+    else
+        img = cursor->pixmap().toImage();
+
+    // convert to supported format if necessary
+    if (!display->shm()->formatSupported(img.format())) {
+        if (mask.isNull()) {
+            img.convertTo(QImage::Format_RGB32);
+        } else {
+            // preserve mask
+            img.convertTo(QImage::Format_ARGB32);
+            QPixmap pixmap = QPixmap::fromImage(img);
+            pixmap.setMask(mask);
+            img = pixmap.toImage();
+        }
+    }
+
     QSharedPointer<QWaylandShmBuffer> buffer(new QWaylandShmBuffer(display, img.size(), img.format()));
     memcpy(buffer->image()->bits(), img.bits(), size_t(img.sizeInBytes()));
     return buffer;
-- 
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