window: Don't set invalid csd input shape

This might happen if the CSS values of the decoration node are broken,
e.g. if people *accidentally* type large negative values for the
margins.

Fixes #2268

diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 9e056fe774f8e6d41615ba954fd5373467932061..6a58f55a02f0608db3432e4b9e0005e2407c6d3d 100644 (file)
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -5361,7 +5361,6 @@ update_csd_shape (GtkWindow *window)
 {
   GtkWidget *widget = (GtkWidget *)window;
   GtkWindowPrivate *priv = gtk_window_get_instance_private (window);
-  cairo_region_t *region;
   cairo_rectangle_int_t rect;
   GtkBorder border, tmp;
   GtkBorder window_border;
@@ -5392,9 +5391,13 @@ update_csd_shape (GtkWindow *window)
   rect.y = window_border.top;
   rect.width = gtk_widget_get_allocated_width (widget) - window_border.left - window_border.right;
   rect.height = gtk_widget_get_allocated_height (widget) - window_border.top - window_border.bottom;
-  region = cairo_region_create_rectangle (&rect);
-  gtk_widget_set_csd_input_shape (widget, region);
-  cairo_region_destroy (region);
+
+  if (rect.width > 0 && rect.height > 0)
+    {
+      cairo_region_t *region = cairo_region_create_rectangle (&rect);
+      gtk_widget_set_csd_input_shape (widget, region);
+      cairo_region_destroy (region);
+    }
 }
 
 static void