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

[Simon Peeters]

On wo, 2016-03-30 at 20:15 +0600, Vadim A. Misbakh-Soloviov wrote:
> 	Error verifying signature: Cannot verify message signature:
> Incorrect message format
> The issue is already discussed (although, I'd like to hear new
> optinions, with 
> another solutions) on the lists (here, and in "devel". You can find
> discussion 
> tails by searching for "IPP backend bug" subject in both lists
> (messages are 
> partially here and there).
> Here is some points:
> http://www.cups.org/pipermail/cups-devel/2014-October/015414.html
> (notice Mike's answer ^)
> http://www.cups.org/pipermail/cups-devel/2015-September/016432.html
> http://www.cups.org/pipermail/cups-devel/2015-September/016436.html
> http://www.cups.org/pipermail/cups-devel/2015-September/016441.html
> 
> // Unfortunatelly, it is a bit hard to just point to entire thread.
> 
> 
> TL;DR: Use Generic/* drivers on remote CUPS'es, and not the same
> driver.

hmm, if i put it on "Generic PDF Printer"(picked that one since I think
i remember cups uses pdf internally) i get "Can't detect file type" on
the server. but "ipp everywhere" seems to work.

> When you're using same foomatic driver on both sides there is
> filters 
> collision occurs.
> By the way, there was no such thing while filters was in same package
> with 
> cups, and not a separate project), and there was ok to use same
> driver on both 
> sides (just like on windows).

Yeah, I think it's wierd that it:
 a) used to work
 b) still works from windows

> By the way too, one of the negative points of using it in that way —
> it is 
> impossible to, say, remotelly clean print heads using generic drivers
> :(

Luckily i can live with this. (I can clean the printheads from the cups
web interface)

> 
> P.S. As I said, I'd VERY like to hear some dev optinion about the way
> to avoid 
> Generic drivers usage.