An old link still knows the way

The first post on this site is about a photo that disappeared from a 2012 blog entry while the link to it kept working. Link rot is the reason this engine exists, so an engine that quietly broke its own URLs would be a bad joke.

Renaming a post changes its address. That's unavoidable — the slug is the URL. What's avoidable is the old address turning into a 404.

What renaming does now

Rename a post — r in the properties dialog — and the post records its old address inside itself. The build then keeps a one-page redirect standing at every address the post has ever had.

The link in a two-year-old toot keeps resolving. The link somebody put in their own blog post keeps resolving. You get to fix a slug you regret without the fix costing you every reference to it that already exists in the world.

The redirects belong to the post

They live and die with it. Unpublish the post and its redirects come off the site with it — a redirect pointing into nothing is just a slower 404. Publish it again and they come back, because the old links didn't stop existing while the post was away.

That's the same rule the announcement toot follows, and for the same reason: everything a post owns should leave and return with it, or the site accumulates debris nobody remembers creating.

The small print

The redirect list is the post's own history, so it never contains the post's current address — a post redirecting to itself is a loop, and the build says so if a date edit across a year boundary ever creates one.

And slugs have a length limit now, with a plain message when you exceed it. The first version handed you a filesystem error instead, which is a technically accurate way of saying nothing useful at all.