Register lib/ directories of themes as PSR-0 roots for Drupal\$theme namespace

Is there any reason not to?
The argument was that most themes do not have classes (other than tests), but does it hurt to enable PSR-0 autoloading for those that do have classes?

The theme system is scheduled to be gutted by a series of sprints starting this weekend. We may want to wait until then to spend more time on this. Certainly IF a theme is going to include classes, they should be PSR-0-loaded, no question. Whether or not it will, we don't know yet.

In regards to tests, the latest patch of #1477218: Convert Tracker tests to PSR-0 / PSR-0 test class discovery now registers the namespace for everything living in {system}.

I don't think this needs much discussion. Themes won't be "PHP-less" anytime soon, so it would be very strange to not support class autoloading for themes for no apparent reason.

Isn't this "works as designed" via #3, then?

#3 was about tests only.

However, looking at system_list(), it's possible that this already works. We should add a test to confirm that.

Something like this then, probably?

Yup :)

#7: 1538478-theme-class-loading-7.patch queued for re-testing.

Reroll.

Oh ... failed properly rerolling. It's test_theme, not theme_test.

Thank you :)

Committed and pushed to 8.x. Thanks!