[asterisk-dev] Clearing pick-up groups on Zap/ channels

[Gil Kloepfer]

I've discovered that in configuration files such as the one for
chan_zap (where all the options "cascade down" rather than being
specific for each category, there is no way to indicate that
channels have no pick-up group after the first group has been
set.  For example (simplified), in zapata.conf:

  [channels]
  ; These two phones are in call group/pick-up group #1
  callerid="Green Phone"<(256) 428-6121>
  callgroup=1
  pickupgroup=1
  channel => 1 
  callerid="Black Phone"<(256) 428-6122>
  channel => 2
  
  ; These three channels should not be in ANY pick-up groups, but there
  ; is no way to clear the previous settings
  callerid="CallerID Phone" <(256) 428-6123>
  channel => 3
  callerid="CallerID Phone" <(256) 704-4666>
  channel => 4
  callerid="CallerID Phone" <(630) 372-1564>
  channel => 5

In the case of channels 3, 4, and 5, there is no valid way to "clear out"
the "current" callgroup / pickupgroup without encountering an error
(you could say pickupgroup=none, but that actually throws an error
from ast_get_group(), although it happens to work).

I'd like to propose making a change to ast_get_group() to allow
the option "none" that returns a ast_group_t containing no groups set,
basically zero.  So you could say 'callgroup=none' for example.

Note that callgroup=0 would not do what I am suggesting because 0 is
a valid group number.  The group/callgroup/pickupgroup is actually a
bit mask (bits numbered 0 to 63).

If this seems reasonable, please indicate so and I will submit a patch
for both 1.2 and -trunk (they are essentially the same patch).

Thanks.

BTW: It was great meeting those of you who I did meet at Astricon.

---
Gil Kloepfer
astr-dev at kloepfer.org