[gtk+/gtk-3-4] GtkFontSel: Don't try to set the cursor on invalid iters

[Matthias Clasen <matthiasc src gnome org>]

commit 0634796aa6ce15221daad8bf1d5db27128d8d148
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jun 1 16:58:36 2012 -0400

    GtkFontSel: Don't try to set the cursor on invalid iters
    
    This causes a lot of warnings.
    https://bugzilla.gnome.org/show_bug.cgi?id=677293

 gtk/deprecated/gtkfontsel.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/deprecated/gtkfontsel.c b/gtk/deprecated/gtkfontsel.c
index ca5c6e0..f09b2d4 100644
--- a/gtk/deprecated/gtkfontsel.c
+++ b/gtk/deprecated/gtkfontsel.c
@@ -1053,7 +1053,8 @@ gtk_font_selection_show_available_sizes (GtkFontSelection *fontsel,
 	      found = TRUE;
 	    }
 
-	  gtk_tree_model_iter_next (GTK_TREE_MODEL (model), &iter);
+          if (!gtk_tree_model_iter_next (GTK_TREE_MODEL (model), &iter))
+            break;
 	}
 
       if (!found)