Support _NET_WORKAREA on Xinerama setups in QDesktopWidget

Instead of ignoring _NET_WORKAREA, merge it with each screen geometry
to give a meaningful availableGeometry() for all screens.

Reviewed-by: denis

1 files changed, 18 insertions, 8 deletions

diff --git a/src/gui/kernel/qdesktopwidget_x11.cpp b/src/gui/kernel/qdesktopwidget_x11.cpp
index 1555fc0..8b0c215 100644
--- a/src/gui/kernel/qdesktopwidget_x11.cpp
+++ b/src/gui/kernel/qdesktopwidget_x11.cpp
@@ -285,26 +285,36 @@ const QRect QDesktopWidget::availableGeometry(int screen) const
     if (d->workareas[screen].isValid())
         return d->workareas[screen];
 
-    if ((d->screenCount == 1 || !isVirtualDesktop())
-        && X11->isSupportedByWM(ATOM(_NET_WORKAREA))) {
+    if (X11->isSupportedByWM(ATOM(_NET_WORKAREA))) {
+        int x11Screen = isVirtualDesktop() ? DefaultScreen(X11->display) : screen;
+
         Atom ret;
         int format, e;
         unsigned char *data = 0;
         unsigned long nitems, after;
 
         e = XGetWindowProperty(X11->display,
-                                QX11Info::appRootWindow(screen),
-                                ATOM(_NET_WORKAREA), 0, 4, False, XA_CARDINAL,
-                                &ret, &format, &nitems, &after, &data);
+                               QX11Info::appRootWindow(x11Screen),
+                               ATOM(_NET_WORKAREA), 0, 4, False, XA_CARDINAL,
+                               &ret, &format, &nitems, &after, &data);
 
+        QRect workArea;
         if (e == Success && ret == XA_CARDINAL &&
             format == 32 && nitems == 4) {
             long *workarea = (long *) data;
-            d->workareas[screen].setRect(workarea[0], workarea[1],
-                                          workarea[2], workarea[3]);
+            workArea = QRect(workarea[0], workarea[1], workarea[2], workarea[3]);
         } else {
-            d->workareas[screen] = screenGeometry(screen);
+            workArea = screenGeometry(screen);
+        }
+
+        if (isVirtualDesktop()) {
+            // intersect the workarea (which spawns all Xinerama screens) with the rect for the
+            // requested screen
+            workArea &= screenGeometry(screen);
         }
+
+        d->workareas[screen] = workArea;
+
         if (data)
             XFree(data);
     } else {