What if the Default theme is missing?

[technosailor]

The expected behavior of WordPRess is that if the theme set in the database becomes unavailable because of deletion or file permissions, the default Kubrick theme is used instead.

The bug exists in that if the default theme also doesn't exist, the site breaks.

My suggestion is that if default is also unavailable that the first theme that IS available is used instead. Only if there are no themes should a site completely die - and even then, well, there could always be a plaintext rendering.

As far as my understanding goes, the default theme should *always* be there. Can we rely on another theme having a certain template? I wouldn't really want to.

But what *if* it isn't? ;) I realize some will argue the point that Enterprises are niche, however, in our case we have chosen to remove classic and default for the sake of efficiency. I have to add it back which isn't really that bad all things considered - but, it highlights the problem.

Logic says that yes default will be there 99% of the time but in the off chance that someone does what we have or goes and deltes the theme for their own reasons, do we *really* want WP to break?

I would argue that we don't and we should find a way to make sure that if all else fails, we can programmatically still serve the site.

Patch to display error message under these conditions.

It's not going to be a straight forward task to have WordPress generate even basic output without a theme present on the system. I've created this patch which will tell you why WordPress is broken when the default theme and the selected theme are missing.

We no longer revert to the default theme if there is a problem with the current theme.