Hi, I'm updating some links in old documentation; but haven't
found a way to show links to old bugs.

For example, old links like:

	http://redmine.ruby-lang.org/issues/show/2962
	http://redmine.ruby-lang.org/issues/show/4338

do not work anymore and give me 404 (they used to redirect to
to "https://bugs.ruby-lang.org").

When I try updating to "https://bugs.ruby-lang.org",

	https://bugs.ruby-lang.org/issues/2962
	https://bugs.ruby-lang.org/issues/4338

It gives 403 errors, even if I am logged in (as normalperson).
Newer bugs do not seem to exhibit this problem, and I can
view https://bugs.ruby-lang.org/issues/10831 without logging in.

What is happening here?  Thanks.