commit https://github.com/vim/vim/commit/257095760732597983bdd026e791907b7980e295 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Aug 26 20:41:16 2016 +0200 patch 7.4.2262 Problem: Fail to read register content from viminfo if it is 438 characters long. (John Chen) Solution: Adjust the check for line wrapping. (closes https://github.com/vim/vim/issues/1010)

--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -2526,7 +2526,7 @@ barline_writestring(FILE *fd, char_u *s,
 	else
 	    ++len;
     }
-    if (len > remaining)
+    if (len > remaining - 2)
     {
 	fprintf(fd, ">%d\n|<", len);
 	remaining = LSIZE - 20;