Merge: detect already-applied inserts at the end of files

* src/merge.c: When a hunk has fewer suffix than prefix context lines,
try matching to the end of the file instead of doing a "greedy match":
this allows to detect already-applied inserts at the end of the file.
* tests/merge: Add test cases for this.

1 files changed, 30 insertions, 0 deletions

diff --git a/tests/merge b/tests/merge
index 0a3c7ff..98c5705 100644
--- a/tests/merge
+++ b/tests/merge
@@ -166,6 +166,36 @@ a
 4
 EOF
 
+check 'x 2  1ia 1ib -- 1ia 1ib' <<EOF
+Hunk #1 already applied at 1-2.
+a
+b
+1
+2
+
+Hunk #1 already applied at 1-2.
+a
+b
+1
+2
+
+EOF
+
+check 'x 2  2aa 2ab -- 2aa 2ab' <<EOF
+Hunk #1 already applied at 3-4.
+1
+2
+a
+b
+
+Hunk #1 already applied at 3-4.
+1
+2
+a
+b
+
+EOF
+
 # ==============================================================
 
 check 'x 4  2d -- 3d' <<EOF