Free/Busy "find availibility" in Roundcube

[hede]

Any one using "find availibility" in Roundcube?

For me free-busy-planning is working within kontact, including those
"time-bars" (I don't know how it's called, neither in german nor in
english, nor in any other language...)

In roundcube free-busy is partly worlking if I login at my local PC
via a local IP. If I edit an event and add participants, the
"Avail."-column gets green or red. But "Find availibility..." still is
empty.

If I login via https and a public IP, free-busy doen't work at all.
(Avail."-column remains empty and no time-bars in "find availibility".

The former one seems to be a bug in the "find availibility"-javascript,
because at the server it successfully requests free-busy data. The
later one seems to be because "kolab-freebusy" is configured to ask for
a name and password from foreign/untrusted IPs. And roundcube seems to
not forward those. (the user is logged in with the correct credentials)

hede