diff -r 4bd67ae7d75a -r 9a8363d23419 tests/test-bdiff.py
--- a/tests/test-bdiff.py	Thu Apr 21 21:53:18 2016 -0500
+++ b/tests/test-bdiff.py	Thu Apr 21 21:05:26 2016 -0500
@@ -52,6 +52,9 @@
         pos += l
 showdiff("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\nx\n\nz\n")
 showdiff("x\n\nx\n\nx\n\nx\n\nz\n", "x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n")
+# we should pick up abbbc. rather than bc.de as the longest match
+showdiff("a\nb\nb\nb\nc\n.\nd\ne\n.\nf\n",
+         "a\nb\nb\na\nb\nb\nb\nc\n.\nb\nc\n.\nd\ne\nf\n")
 
 print("done")