Re: [Pan-users] RFC versus sever versus client

[Per Hedeland]

On 2016-11-12 15:43, Per Hedeland wrote:
> 
> And in the specific case of the MODE READER command, with the specific
> reply code 500 - which means "Command not understood" - it is useful,
> and can even be considered reasonable, to ignore the reply. The client
> doesn't *need* any result from the command (unlike e.g. LIST) in order
> to proceed - it is just issuing it because some *servers* need it to be
> issued in order to allow reader commands such as LIST. (In INN, a
> special "reader service" program 'nnrpd' is forked at that point - the
> reader commands are not implemented in the "main" 'innd' program which
> is dedicated to "feeder service".)
> 
> I.e. if the server says "Command not understood" in response to MODE
> READER, it obviously does *not* need that command, and it's perfectly OK
> for the client to go on with its reader business.

...and in case there is interest in it, the attached patch for Pan does
just that - I've tested it against what I believe is the server the OP
is referring to, in any case it is one that does return 500 for MODE
READER.

--Per

PS It so happens that Pan also uses MODE READER as a "keepalive
function", i.e. it is issued periodically as a no-op to keep server
connections alive...

pan.diff
Description: Bourne shell script