Fixed lost flushes in raster window surface.

Occasionally we get regions with bounding rects outside the widget, so
we need to take care to clip against both the native widget and the
raster surface's image rect.

Task-number: QTBUG-17813
Reviewed-by: Gunnar Sletta

1 files changed, 11 insertions, 10 deletions

diff --git a/src/gui/painting/qwindowsurface_raster.cpp b/src/gui/painting/qwindowsurface_raster.cpp
index d972384..15ff044 100644
--- a/src/gui/painting/qwindowsurface_raster.cpp
+++ b/src/gui/painting/qwindowsurface_raster.cpp
@@ -229,7 +229,6 @@ void QRasterWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoi
     QRegion wrgn(rgn);
     if (!wOffset.isNull())
         wrgn.translate(-wOffset);
-    QRect wbr = wrgn.boundingRect();
 
     if (wrgn.rectCount() != 1) {
         int num;
@@ -237,23 +236,25 @@ void QRasterWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoi
         XSetClipRectangles(X11->display, d_ptr->gc, 0, 0, rects, num, YXBanded);
     }
 
-    QRect br = rgn.boundingRect().translated(offset);
+    QPoint widgetOffset = offset + wOffset;
+    QRect clipRect = widget->rect().translated(widgetOffset).intersected(d_ptr->image->image.rect());
+
+    QRect br = rgn.boundingRect().translated(offset).intersected(clipRect);
+    QPoint wpos = br.topLeft() - widgetOffset;
+
 #ifndef QT_NO_MITSHM
     if (d_ptr->image->xshmpm) {
         XCopyArea(X11->display, d_ptr->image->xshmpm, widget->handle(), d_ptr->gc,
-                  br.x(), br.y(), br.width(), br.height(), wbr.x(), wbr.y());
+                  br.x(), br.y(), br.width(), br.height(), wpos.x(), wpos.y());
         d_ptr->needsSync = true;
     } else if (d_ptr->image->xshmimg) {
-        const QImage &src = d->image->image;
-        br = br.intersected(src.rect());
         XShmPutImage(X11->display, widget->handle(), d_ptr->gc, d_ptr->image->xshmimg,
-                     br.x(), br.y(), wbr.x(), wbr.y(), br.width(), br.height(), False);
+                     br.x(), br.y(), wpos.x(), wpos.y(), br.width(), br.height(), False);
         d_ptr->needsSync = true;
     } else
 #endif
     {
         const QImage &src = d->image->image;
-        br = br.intersected(src.rect());
         if (src.format() != QImage::Format_RGB32 || widget->x11Info().depth() < 24) {
             Q_ASSERT(src.depth() >= 16);
             const QImage sub_src(src.scanLine(br.y()) + br.x() * (uint(src.depth()) / 8),
@@ -262,11 +263,11 @@ void QRasterWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoi
             data->xinfo = widget->x11Info();
             data->fromImage(sub_src, Qt::NoOpaqueDetection);
             QPixmap pm = QPixmap(data);
-            XCopyArea(X11->display, pm.handle(), widget->handle(), d_ptr->gc, 0 , 0 , br.width(), br.height(), wbr.x(), wbr.y());
+            XCopyArea(X11->display, pm.handle(), widget->handle(), d_ptr->gc, 0 , 0 , br.width(), br.height(), wpos.x(), wpos.y());
         } else {
             // qpaintengine_x11.cpp
             extern void qt_x11_drawImage(const QRect &rect, const QPoint &pos, const QImage &image, Drawable hd, GC gc, Display *dpy, Visual *visual, int depth);
-            qt_x11_drawImage(br, wbr.topLeft(), src, widget->handle(), d_ptr->gc, X11->display, (Visual *)widget->x11Info().visual(), widget->x11Info().depth());
+            qt_x11_drawImage(br, wpos, src, widget->handle(), d_ptr->gc, X11->display, (Visual *)widget->x11Info().visual(), widget->x11Info().depth());
         }
     }
 
@@ -311,7 +312,7 @@ void QRasterWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoi
     }
     CGContextClip(context);
 
-    QRect r = rgn.boundingRect();
+    QRect r = rgn.boundingRect().intersected(d->image->image.rect());
     const CGRect area = CGRectMake(r.x(), r.y(), r.width(), r.height());
     CGImageRef image = CGBitmapContextCreateImage(d->image->cg);
     CGImageRef subImage = CGImageCreateWithImageInRect(image, area);