commit https://github.com/vim/vim/commit/d3c907b5d2b352482b580a0cf687cbbea4c19ea1 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Aug 17 21:32:09 2016 +0200 patch 7.4.2223 Problem: Buffer overflow when using latin1 character with feedkeys(). Solution: Check for an illegal character. Add a test.

--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -4370,7 +4370,7 @@ dump_pipe(int	    options,
 	     * round. */
 	    for (p = buffer; p < buffer + len; p += l)
 	    {
-		l = mb_cptr2len(p);
+		l = MB_CPTR2LEN(p);
 		if (l == 0)
 		    l = 1;  /* NUL byte? */
 		else if (MB_BYTE2LEN(*p) != l)