The Theming app injects the stylesheets for the different themes in the
"<header>" element of the page, and those stylesheets are then loaded by
the browser from a "Controller" (a plain "Controller", not an
"OCSController"). The stylesheets, in turn, may also get some images
(like the background) also from the "Controller".
When handling a request to "index.php" it is checked whether the user is
logged in and, if not, a login is tried. A disabled user is explicitly
seen as not logged in, so a login is always tried in that case, but
disabled users are also explicitly prevented to log in, so the login
also fails. Due to that trying to get any of the themed stylesheets or
images with a disabled account (to be able to show the "Account
disabled" error page) fails with an HTTP status 401.
To solve that, and to avoid touching this basic logic as much as
possible, the login exception is now ignored (if the user is disabled)
for some specific requests to the Theming app.
The clouds.jpg file was not available in stable30, so the file and its
license were copied from the commit that introduced them in newer
branches, 19ce362896.
Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>
c6f870245a