commit https://github.com/vim/vim/commit/45d2eeaad66939348893b9254171067b0457cd9d Author: Bram Moolenaar <Bram@vim.org> Date: Mon Jun 6 21:07:52 2016 +0200 patch 7.4.1903 Problem: When writing viminfo merging current history with history in viminfo may drop recent history entries. Solution: Add new format for viminfo lines, use it for history entries. Use a timestamp for ordering the entries. Add test_settime(). Add the viminfo version. Does not do merging on timestamp yet.

--- a/src/structs.h
+++ b/src/structs.h
@@ -1014,6 +1014,7 @@ typedef struct
 #ifdef FEAT_MBYTE
     vimconv_T	vir_conv;	/* encoding conversion */
 #endif
+    int		vir_version;	/* viminfo version detected or -1 */
     garray_T	vir_barlines;	/* lines starting with | */
 } vir_T;