widget: gdk_display_get_monitor can return NULL

Fixes #1466

diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 2b39f28f398e20244cf1ae8fdb7b2caa3935aff0..587bf81b0fd5b02ca5215aae4a7f70a6c4eda07b 100644 (file)
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -7617,7 +7617,10 @@ gtk_widget_get_scale_factor (GtkWidget *widget)
   display = _gtk_widget_get_display (widget);
   monitor = gdk_display_get_monitor (display, 0);
 
-  return gdk_monitor_get_scale_factor (monitor);
+  if (monitor)
+    return gdk_monitor_get_scale_factor (monitor);
+
+  return 1;
 }
 
 /**