[dev] Bug #13319: possible fix

[Jasper Olbrich]

Hello,

I think I've implemented a fix for http://bugs.horde.org/ticket/13319.
The main problem is that external calendars are no longer working if 
they expect HTTP Basic Auth.

The problem is that in kronolith/lib/Driver/Ical.php the variable 
$sabreOptions['userName'] is set, but this breaks the request method in
pear/php/Horde/Dav/Client.php because the authType of the SabreDAV 
client is AUTH_BASIC | AUTH_DIGEST. That leads to the DIGEST method 
being used in the Horde_Dav_Client class.

My idea is to use the HTTP 401 response from the external calendar 
provider when the user is adding the external calendar, because that's 
the place where the provider tells us which authentication mode is required.

In my (AFAI can tell, working) solution, this information is collected 
in Horde/Dav/Client.php and passed along using the Horde_Dav_Exception 
and the following Kronolith_Exception back to the Browser.

Then the user enters his credentials and the desired authentication mode 
is sent back to the horde server as well. There it is used to access the 
calendar provider and finally stored in the database.

I don't know why the user name is set in the sabreOptions in the first 
place (the change was introduced here 
https://github.com/horde/horde/commit/477f2c46041bde1b3bfa572d7fbac535046c3be6#diff-2a209d195528a6339e273da67af8fd86), 
but now something has to be done to fix this. If my approach is not 
completely wrong, I could provide a patch. Should I attach it to the bug 
tracker ticket?

Or are there other, better ways to get the external calendars working again?

-- 
Jasper