readline.c: $SAFE 4

* ext/readline/readline.c (readline_s_delete_text): call rb_secure
  only if level 4 is allowed.  otherwise do nothing.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42114 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/readline/readline.c

@@ -578,7 +578,9 @@ readline_s_insert_text(VALUE self, VALUE str)
 static VALUE
 readline_s_delete_text(int argc, VALUE *argv, VALUE self)
 {
-    rb_secure(RUBY_SAFE_LEVEL_MAX);
+#if RUBY_SAFE_LEVEL_MAX >= 4
+    rb_secure(4);
+#endif
     rb_check_arity(argc, 0, 2);
     if (rl_line_buffer) {
 	char *p, *ptr = rl_line_buffer;