patch 7.4.2217
Problem:    When using matchaddpos() a character after the end of the line can
            be highlighted.
Solution:   Only highlight existing characters. (Hirohito Higashi)
diff --git a/src/structs.h b/src/structs.h
index 2a64471..4488bf8 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2439,6 +2439,8 @@
     linenr_T	first_lnum;	/* first lnum to search for multi-line pat */
     colnr_T	startcol; /* in win_line() points to char where HL starts */
     colnr_T	endcol;	 /* in win_line() points to char where HL ends */
+    int		is_addpos;	/* position specified directly by
+				   matchaddpos(). TRUE/FALSE */
 #ifdef FEAT_RELTIME
     proftime_T	tm;	/* for a time limit */
 #endif