bug#33054: 25.2; diff-model: M-k kills wrong hunk

[Dima Kogan]

I'm using a very recent build: e4896856172

Steps to reproduce bug:

- Open attached diff. Emacs should open it in diff-mode
- Put point on 'd' in the second "diff": (goto-char 98)
- M-k

This should kill the hunk we're on. We are unambiguously sitting on the
second hunk, but the latest diff-mode is confused, thinks we're on the
first hunk, and kills that instead. Kinda. Moving the point even one
character forward makes it work.

diff --git a/111.py b/111.py
--- a/111.py
+++ b/111.py
@@ -154,3 +154,3 @@
 
-    aaa
+    bbb
 
diff --git a/222.py b/222.py
--- a/222.py
+++ b/222.py
@@ -224,3 +230,3 @@ writemodel(m_to)
     asdf
-    21234
+    345
     zxcv