From b61a305039a58ac0c2ff095b22e4eb6d7ccfc89e Mon Sep 17 00:00:00 2001
From: ckelsel <ckelsel@hotmail.com>
Date: Mon, 8 Jan 2018 12:23:33 +0800
Subject: [PATCH] vim-patch:8.0.0351: no test for concatenating an empty string

Problem:    No test for concatenating an empty string that results from out of
            bounds indexing.
Solution:   Add a simple test.

https://github.com/vim/vim/commit/218426896cbb2129aa4e85803ea97c5b57df1eaa
---
 src/nvim/testdir/test_expr.vim | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/nvim/testdir/test_expr.vim b/src/nvim/testdir/test_expr.vim
index d32facaa98..ad967c528c 100644
--- a/src/nvim/testdir/test_expr.vim
+++ b/src/nvim/testdir/test_expr.vim
@@ -439,3 +439,8 @@ func Test_funcref()
   call assert_equal(2, OneByRef())
   call assert_fails('echo funcref("{")', 'E475:')
 endfunc
+
+func Test_empty_concatenate()
+  call assert_equal('b', 'a'[4:0] . 'b')
+  call assert_equal('b', 'b' . 'a'[4:0])
+endfunc