updated for version 7.3.606
Problem:    CTRL-P completion has a problem with multi-byte characters.
Solution:   Check for next character being NUL properly.  (Yasuhiro Matsumoto)
diff --git a/src/search.c b/src/search.c
index 1db967d..e231a3a 100644
--- a/src/search.c
+++ b/src/search.c
@@ -5141,7 +5141,7 @@
 		    && !(compl_cont_status & CONT_SOL)
 #endif
 		    && *startp != NUL
-		    && *(p = startp + 1) != NUL)
+		    && *(p = startp + MB_PTR2LEN(startp)) != NUL)
 		goto search_line;
 	}
 	line_breakcheck();