[meld] Don't merge diffs for two-way comparisons

[Kai Willadsen <kaiw src gnome org>]

commit b7cd945e0c64e879b76161a53ed78f89695e372f
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Fri Jun 26 08:46:38 2009 +1000

    Don't merge diffs for two-way comparisons

 diffutil.py |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/diffutil.py b/diffutil.py
index 019b778..3da1c1a 100644
--- a/diffutil.py
+++ b/diffutil.py
@@ -77,7 +77,10 @@ class Differ(object):
         self._merge_cache = []
 
     def _update_merge_cache(self, texts):
-        self._merge_cache = [c for c in self._merge_diffs(self.diffs[0], self.diffs[1], texts)]
+        if self.num_sequences == 3:
+            self._merge_cache = [c for c in self._merge_diffs(self.diffs[0], self.diffs[1], texts)]
+        else:
+            self._merge_cache = [(c, None) for c in self.diffs[0]]
 
     def change_sequence(self, sequence, startidx, sizechange, texts):
         assert sequence in (0, 1, 2)