[gthumb] GthImageViewer: do not use the rgba visual

[Paolo Bacchilega <paobac src gnome org>]

commit 91fbcc1b2f93dd37d9a1da1d51866152d63821a6
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Nov 1 20:03:08 2013 +0100

    GthImageViewer: do not use the rgba visual

 gthumb/gth-image-viewer.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/gthumb/gth-image-viewer.c b/gthumb/gth-image-viewer.c
index 985d4c7..ae70bba 100644
--- a/gthumb/gth-image-viewer.c
+++ b/gthumb/gth-image-viewer.c
@@ -1541,6 +1541,14 @@ gth_image_viewer_init (GthImageViewer *self)
                          "value_changed",
                          G_CALLBACK (vadj_value_changed),
                          self);
+
+       /* do not use the rgba visual on the drawing area */
+       {
+               GdkVisual *visual;
+               visual = gdk_screen_get_system_visual (gtk_widget_get_screen (GTK_WIDGET (self)));
+               if (visual != NULL)
+                       gtk_widget_set_visual (GTK_WIDGET (self), visual);
+       }
 }