[gtk] tooltips: Don't use a cursor_size of 0

[Matthias Clasen <matthiasc src gnome org>]

commit 058986714c5e21b91d3a4d85a410ee2e940394e0
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Mar 31 16:16:01 2019 -0400

    tooltips: Don't use a cursor_size of 0
    
    This leads to flickering tooltips.

 gtk/gtktooltip.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gtk/gtktooltip.c b/gtk/gtktooltip.c
index f5c155c2a3..f309fc7683 100644
--- a/gtk/gtktooltip.c
+++ b/gtk/gtktooltip.c
@@ -603,6 +603,9 @@ gtk_tooltip_position (GtkTooltip *tooltip,
                 "gtk-cursor-theme-size", &cursor_size,
                 NULL);
 
+  if (cursor_size == 0)
+    cursor_size = 16;
+
   if (device)
     anchor_rect_padding = MAX (4, cursor_size - 32);
   else