Merge remote-tracking branch 'origin/5.12' into 5.13

Change-Id: Ie7f68dcd5650e0037b6c3313cc9ffdcd7c494fbe

1 files changed, 7 insertions, 3 deletions

diff --git a/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11.cpp b/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11.cpp
index 2688d6e884..3377eeaae9 100644
--- a/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11.cpp
+++ b/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11.cpp
@@ -200,6 +200,7 @@ public:
     uint has_pattern : 1;
     uint has_alpha_pen : 1;
     uint has_alpha_brush : 1;
+    uint use_sysclip : 1;
     uint render_hints;
 
     const QXcbX11Info *xinfo;
@@ -701,6 +702,9 @@ bool QX11PaintEngine::begin(QPaintDevice *pdev)
     d->xlibMaxLinePoints = 32762; // a safe number used to avoid, call to XMaxRequestSize(d->dpy) - 3;
     d->opacity = 1;
 
+    QX11PlatformPixmap *x11pm = paintDevice()->devType() == QInternal::Pixmap ? qt_x11Pixmap(*static_cast<QPixmap *>(paintDevice())) : nullptr;
+    d->use_sysclip = paintDevice()->devType() == QInternal::Widget || (x11pm ? x11pm->isBackingStore() : false);
+
     // Set up the polygon clipper. Note: This will only work in
     // polyline mode as long as we have a buffer zone, since a
     // polyline may be clipped into several non-connected polylines.
@@ -1472,7 +1476,7 @@ void QX11PaintEngine::updatePen(const QPen &pen)
     }
 
     if (!d->has_clipping) { // if clipping is set the paintevent clip region is merged with the clip region
-        QRegion sysClip = systemClip();
+        QRegion sysClip = d->use_sysclip ? systemClip() : QRegion();
         if (!sysClip.isEmpty())
             x11SetClipRegion(d->dpy, d->gc, 0, d->picture, sysClip);
         else
@@ -1603,7 +1607,7 @@ void QX11PaintEngine::updateBrush(const QBrush &brush, const QPointF &origin)
     vals.fill_style = s;
     XChangeGC(d->dpy, d->gc_brush, mask, &vals);
     if (!d->has_clipping) {
-        QRegion sysClip = systemClip();
+        QRegion sysClip = d->use_sysclip ? systemClip() : QRegion();
         if (!sysClip.isEmpty())
             x11SetClipRegion(d->dpy, d->gc_brush, 0, d->picture, sysClip);
         else
@@ -2223,7 +2227,7 @@ void QX11PaintEngine::updateMatrix(const QTransform &mtx)
 void QX11PaintEngine::updateClipRegion_dev(const QRegion &clipRegion, Qt::ClipOperation op)
 {
     Q_D(QX11PaintEngine);
-    QRegion sysClip = systemClip();
+    QRegion sysClip = d->use_sysclip ? systemClip() : QRegion();
     if (op == Qt::NoClip) {
         d->has_clipping = false;
         d->crgn = sysClip;