vim-patch:7.4.1782

Problem:    strcharpart() does not work properly with some multi-byte
            characters.
Solution:   Use mb_cptr2len() instead of mb_char2len(). (Hirohito Higashi)

fca6600305

src/nvim/eval.lua

@@ -272,7 +272,7 @@ return {
     strchars={args={1,2}},
     strdisplaywidth={args={1, 2}},
     strftime={args={1, 2}},
-    strgetchar={args={2,2}},
+    strgetchar={args={2, 2}},
     stridx={args={2, 3}},
     string={args=1},
     strlen={args=1},