[meld] Fix previous-diff at the end of a file when it doesn't end in a change

[Kai Willadsen <kaiw src gnome org>]

commit 72a243f9b61d4ff580e71020a8566434516c9408
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Mon Mar 15 10:59:04 2010 +1000

    Fix previous-diff at the end of a file when it doesn't end in a change
    
    This bug crept in to the recent cursor-related rework, where we didn't
    make sure that the line cache was filled in for the end of sequences.
    This commit just tags any trailing range at the end of the cache with
    the last prev/next details.

 meld/diffutil.py |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/meld/diffutil.py b/meld/diffutil.py
index 074b386..c634f1c 100644
--- a/meld/diffutil.py
+++ b/meld/diffutil.py
@@ -136,6 +136,11 @@ class Differ(object):
                 self._line_cache[seq][start:end] = [(i, prev[seq], next[seq])] * (end - start)
                 prev[seq], old_end[seq] = i, end
 
+        for seq in range(3):
+            last, end = old_end[seq], len(self._line_cache[seq])
+            if (last < end):
+                self._line_cache[seq][last:end] = [(None, prev[seq], next[seq])] * (end - last)
+
     def _consume_blank_lines(self, c, texts, pane1, pane2):
         if c is None:
             return None