[gnome-sudoku/gnome-3-12] Do not update hints if grid is null

[Michael Catanzaro <mcatanzaro src gnome org>]

commit a9430802d882a480ee79dd257f5284f6bb8da6f0
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sat May 31 19:35:17 2014 -0500

    Do not update hints if grid is null
    
    https://bugzilla.gnome.org/show_bug.cgi?id=633351

 src/lib/gsudoku.py |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/lib/gsudoku.py b/src/lib/gsudoku.py
index 1528ec4..922bd0e 100644
--- a/src/lib/gsudoku.py
+++ b/src/lib/gsudoku.py
@@ -237,6 +237,8 @@ class SudokuGameDisplay (SudokuNumberGrid, GObject.GObject):
             self.hints += 1
 
     def show_hint_for_entry (self, entry, interactive = False):
+        if self.grid == None:
+            return
         if interactive:
             set_method = entry.set_note_text_interactive
         else: