[meld] Fix classification of deleted hunks in middle-pane

[Kai Willadsen <kaiw src gnome org>]

commit bf9f5aa3efa5b3e45d03bf1e7faf8e610c494822
Author: Piotr Piastucki <the_leech users berlios de>
Date:   Mon Jul 6 18:06:06 2009 +0200

    Fix classification of deleted hunks in middle-pane
    
    In situations where a middle-pane hunk does not exist in either left or
    right panes, the hunk was being classified as a modified hunk. This commit
    fixes this problem so that these hunks are now classified as inserted.

 diffutil.py |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/diffutil.py b/diffutil.py
index 907ba7f..c78b07f 100644
--- a/diffutil.py
+++ b/diffutil.py
@@ -221,7 +221,9 @@ class Differ(object):
             else:
                 l0, h0, l1, h1, l2, h2 = self._merge_blocks(using)
                 if h0-l0 == h2-l2 and texts[0][l0:h0] == texts[2][l2:h2]:
-                    if l1 != h1:
+                    if l1 != h1 and l0 == h0:
+                        tag = "delete"
+                    elif l1 != h1:
                         tag = "replace"
                     else:
                         tag = "insert"