Wireshark · Wireshark-users: Re: [Wireshark-users] packet counter statistics for a dissector

[Jeff Morriss <jeff.morriss.ws@xxxxxxxxx>]

Toralf Förster wrote:
> Hello,
>
> for the attached dissector for the Lotus Notes Sametime protocol I added a 
> packet counting statistics based on the Sametime Message Type.
>
> If I click at Statistics -> Sametime -> Packet Counter and define "sametime" 
> as the Filter string I get a correct statistics for the attached stream :
> 6 packets total, 4 with SET_USER_STATUS, 2 CHANNEL_SEND).
>
> However if I do not define a filter string I get :
> 6 packets total, 6 CHANNEL_SEND
>
> In general it seems that only the last Sametime Message Type is used if I do 
> not define a filter string. I cannot find the culprit for that :-(

FWIW this is really a developer question--it might be better asked on 
the -dev list.

The usual cause for different behavior with and without a filter is that 
some (necessary to operate correctly) work is being done by the 
dissector inside an "if(tree)": 'tree' may be NULL if there's no filter 
but it won't be if there is a filter.