patch 8.1.0011: maparg() and mapcheck() confuse empty and non-existing commit https://github.com/vim/vim/commit/f88a5bc10232cc3fac92dba4e8455f4c14311f8e Author: Bram Moolenaar <Bram@vim.org> Date: Mon May 21 13:28:44 2018 +0200 patch 8.1.0011: maparg() and mapcheck() confuse empty and non-existing Problem: maparg() and mapcheck() confuse empty and non-existing. Solution: Return <Nop> for an existing non-empty mapping. (closes https://github.com/vim/vim/issues/2940)

--- a/src/testdir/test_maparg.vim
+++ b/src/testdir/test_maparg.vim
@@ -29,9 +29,13 @@ function Test_maparg()
         \ maparg('foo', '', 0, 1))
 
   map abc x<char-114>x
-  call assert_equal(maparg('abc'), "xrx")
+  call assert_equal("xrx", maparg('abc'))
   map abc y<S-char-114>y
-  call assert_equal(maparg('abc'), "yRy")
+  call assert_equal("yRy", maparg('abc'))
+
+  map abc <Nop>
+  call assert_equal("<Nop>", maparg('abc'))
+  unmap abc
 endfunction
 
 function Test_range_map()