BUG#33057 mysql command line client slows down and uses 100% CPU when restoring dump

client/mysql.cc:
  BUG#33057, avoid calling strlen() *for every single character* in the client's input

client/mysql.cc

@@ -1272,9 +1272,7 @@ static bool add_line(String &buffer,char *line,char *in_string,
   if (status.add_to_history && line[0] && not_in_history(line))
     add_history(line);
 #endif
-#ifdef USE_MB
   char *end_of_line=line+(uint) strlen(line);
-#endif
 
   for (pos=out=line ; (inchar= (uchar) *pos) ; pos++)
   {
@@ -1364,7 +1362,7 @@ static bool add_line(String &buffer,char *line,char *in_string,
       }
     }
     else if (!*ml_comment && !*in_string &&
-             strlen(pos) >= 10 &&
+             (end_of_line - pos) >= 10 &&
              !my_strnncoll(charset_info, (uchar*) pos, 10,
                            (const uchar*) "delimiter ", 10))
     {