winex11: Fetch the current X window position on ShowWindow resulting from a window manager event.

This ensures that we get the correct size for maximized windows too,
which cannot be done with SetWindowPlacement.
diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index a45f04b..3143765 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -2056,6 +2056,48 @@
 }
 
 
+/***********************************************************************
+ *           ShowWindow   (X11DRV.@)
+ */
+UINT X11DRV_ShowWindow( HWND hwnd, INT cmd, RECT *rect, UINT swp )
+{
+    int x, y;
+    unsigned int width, height, border, depth;
+    Window root, top;
+    DWORD style = GetWindowLongW( hwnd, GWL_STYLE );
+    struct x11drv_thread_data *thread_data = x11drv_thread_data();
+    struct x11drv_win_data *data = X11DRV_get_win_data( hwnd );
+
+    if (!data || !data->whole_window || !data->managed || !data->mapped || data->iconic) return swp;
+    if (style & WS_MINIMIZE) return swp;
+
+    /* only fetch the new rectangle if the ShowWindow was a result of a window manager event */
+
+    if (!thread_data->current_event || thread_data->current_event->xany.window != data->whole_window)
+        return swp;
+
+    if (thread_data->current_event->type != ConfigureNotify &&
+        thread_data->current_event->type != PropertyNotify)
+        return swp;
+
+    TRACE( "win %p/%lx cmd %d at %s flags %08x\n",
+           hwnd, data->whole_window, cmd, wine_dbgstr_rect(rect), swp );
+
+    wine_tsx11_lock();
+    XGetGeometry( thread_data->display, data->whole_window,
+                  &root, &x, &y, &width, &height, &border, &depth );
+    XTranslateCoordinates( thread_data->display, data->whole_window, root, 0, 0, &x, &y, &top );
+    wine_tsx11_unlock();
+    rect->left   = x;
+    rect->top    = y;
+    rect->right  = x + width;
+    rect->bottom = y + height;
+    OffsetRect( rect, virtual_screen_rect.left, virtual_screen_rect.top );
+    X11DRV_X_to_window_rect( data, rect );
+    return swp & ~(SWP_NOMOVE | SWP_NOCLIENTMOVE | SWP_NOSIZE | SWP_NOCLIENTSIZE);
+}
+
+
 /**********************************************************************
  *		SetWindowIcon (X11DRV.@)
  *