[meld] Ensure that mergeable states are always Boolean (from Piotr Piastucki)

[Kai Willadsen <kaiw src gnome org>]

commit 2f8b33443c921f1622535e4e4a086d67fe5b86db
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Mon Jun 21 10:21:21 2010 +1000

    Ensure that mergeable states are always Boolean (from Piotr Piastucki)

 meld/diffutil.py |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/meld/diffutil.py b/meld/diffutil.py
index 0533e05..aa25d99 100644
--- a/meld/diffutil.py
+++ b/meld/diffutil.py
@@ -104,8 +104,8 @@ class Differ(gobject.GObject):
 
         mergeable0, mergeable1 = False, False
         for (c0, c1) in self._merge_cache:
-            mergeable0 = mergeable0 or (c0 and c0[0] != 'conflict')
-            mergeable1 = mergeable1 or (c1 and c1[0] != 'conflict')
+            mergeable0 = mergeable0 or (c0 is not None and c0[0] != 'conflict')
+            mergeable1 = mergeable1 or (c1 is not None and c1[0] != 'conflict')
             if mergeable0 and mergeable1:
                 break
         self._has_mergeable_changes = (mergeable0, mergeable1)