[cups] Printing cups -> ipp -> cups -> usb with local drivers

[Johannes Meixner]

Hello,

On Mar 31 20:37 Vadim A. Misbakh-Soloviov wrote (excerpt):
>> q.e.d. - cf.
>> http://www.cups.org/pipermail/cups-devel/2015-September/016450.html
>
> Yes, that was my thread. And I do remember discussion results.
>
>> In general when sending printer-specific data to a CUPS server
>> one must ensure that no duplicate filtering happens.
>
> Yes. But... Can somebody explain how do it work with windows
> and also how does it worked until CUPS-1.6? Wasn't there
> doublefiltering in that situations?

cf.
http://www.cups.org/pipermail/cups-devel/2015-September/016450.html
in particular note what Michael Sweet wrote therein:
------------------------------------------------------------
> The issue is the MIME typing on the CUPS server - if the
> server doesn't recognize the MIME media type then you
> may end up with extra filtering.
>
> I'm not saying it can't work (because we have customers
> that use that configuration all of the time), it is just
> that we get a lot of support calls when people try to do
> Microsoft-style printer sharing to a server that is also
> hosting a CUPS printer driver on the same queue.
------------------------------------------------------------


>> "Unfortunatelly" your kind of setup cannot work reliably.
...
> ... it interfers with the fact it *did* work some years ago.

A setup that cannot work reliably does neither interfer
with that it did work some time ago nor that it might
work again some time in the future.

A setup that cannot work reliably works sometimes
by luck and sometimes fails by bad luck.

If it works or fails depends on uncertain subtle
conditions that may vary all the time.

In your case it seems either the older CUPS or the
older Gutenprint driver or a combination of both or
a combination of both together with older versus
newer filtering rules (i.e. MIME typing rules)
of other filtering software (e.g. traditional
filtering in older CUPS versus newer filtering
via cups-filters) results that it works or fails.


Kind Regards
Johannes Meixner
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