Bug#578079: [Pkg-cups-devel] Bug#578079: I can see this bug too

[Martin-Éric Racine <martin-eric.racine@iki.fi>]

2014/1/10 Didier 'OdyX' Raboud <odyx@debian.org>:
> Control: tags -1 +moreinfo
>
> Hi all,
>
> While hunting down old src:cups bugs, I stumbled upon #578079, which I
> think is not-a-bug, see below.
>
> Le jeudi, 28 avril 2011, 15.56:06 Martin-Éric Racine a écrit :
>> I'm starting to suspect that upstream made some backward-incompatible
>> changes to the way queues are handled, because we get a similar
>> problem with CUPS-PDF, but only whenever the package gets upgraded; if
>> it's installed from scratch or purged then re-installed, it works as
>> it should.
>
> From the code:
>
> $ git grep -B1 'Upgrade Required' cups/
> cups/http-support.c-    case HTTP_STATUS_UPGRADE_REQUIRED :
> cups/http-support.c:        s = _("Upgrade Required");
> $ git grep 'HTTP_STATUS_UPGRADE_REQUIRED ' cups/http.h
> cups/http.h:  HTTP_STATUS_UPGRADE_REQUIRED = 426,
>               /* Upgrade to SSL/TLS required */
>
> … which means that the 'Upgrade Required' error is not a "Please upgrade
> your cups client to a more recent version because we broke backwards-
> compatibility"-error, but a "Hey client, please talk to me over SSL/TLS
> because I require it"-error. This can be enforced using the "Encryption"
> cups.conf statement:
>
>         https://localhost:631/help/ref-cupsd-conf.html#Encryption
>
> I therefore propose to close this bug as it doesn't appear (to me) to be
> a bug but mostly a miscomprehension of the error message.

Way back when people reported installation errors for CUPS-PDF, the
general concensus was that using the -E option to enable encryption
with 'lpadmin' was a source of problem, because the SSL certificates
needed by CUPS might not have been yet unpacked and configured on a
fresh install, so the option was removed from CUPS-PDF's maintainer
scripts.

Yet, according to the above, connections do require it. I'd really
appreciate more precise info for when it's required and when it's not.
Once I've received this, I can upgrade CUPS-PDF's maintainer scripts
to match.

Still, TBH, the error message itself is a textbook example of
obfuscated code that provides misleading feedback to the user. *sigh*

Kudos to Didier for taking the time to figure this one out for everyone else. :)

Martin-Éric