There is no way to start a new call while on an existing call

I tested multiple calls in image 291, to verify it doesn't work before landing this branch. Much to my surprise, it worked.

Dialer -> call someone.
Left-edge swipe -> contacts -> select contact -> call.
Suddenly two calls are active.

I didn't actually think it would work though, and tried to cancel the second call... and, again to my surprise, the 'hang up' button doesn't seem to work in that situation. I had to hang up using the first phone I called, wait for the Ubuntu phone to notice, and then I could make the second call end.

I think I'll wait to continue testing until I can get a third phone in the same room, which should be in a few hours.

This seems to work (tested from silo), except for one issue: After ending one call, the second call stays on hold.

If the calls are merged, it works nicely, and as long as two non-merged calls are active, I can switch between them. But after one non-merged call ends, the other one should still become active if it's not already.

To reproduce this symptom:
- Start one call.
- Tap the contacts icon and use the contacts app to start a second call.
- Hang up one of the two calls without merging them.

Expected result: The remaining call should become active as soon as the other call is done.

Actual result: The remaining call is silenced. However, you can re-activate it by hitting the '>' (play) icon.

This bug was fixed in the package dialer-app - 0.1+14.04.20140411-0ubuntu1

---------------
dialer-app (0.1+14.04.20140411-0ubuntu1) trusty; urgency=low

  [ Gustavo Pichorim Boiko ]
  * Make it possible to start a new call while already in a call. (LP:
    #1306203)
 -- Ubuntu daily release <email address hidden> Fri, 11 Apr 2014 12:49:15 +0000