Re: [Gimp-print-devel] 'make check' failing due to RU translation

[Johannes M. <js...@su...>]

Hello,

On Dec 4 11:30 Solomon Peachy wrote (excerpt):
> On Thu, Dec 05, 2019 at 12:49:54AM +0900, Protea Wines Japan wrote:
>>> Yup, the RU strings tripping the errors are 49 characters taking up 88
>>> bytes.  CUPS has a hardcoded upper limit of 80 characters for these
>>> strings.
>
> (Bah, even I can't get bytes/characters correct in a single paragraph..)
>
>> Ouch .Implied bytes here I guess, if the spec was for 1-byte chars?
>
> Yeah, the spec just treats them as opaque byte sequences.
>
>> Yes, nasty. In PHP, he mb_ functions are the solution, online there
>> are plenty of howto's on cutting off correctly in UTF-8, but messy. I
>> assume we are talking about C code here? Any chance of some library or
>> function that can handle cutting off correctly?
>
> It's a minor PITA, but when we generate the PPDs we can properly
> truncate the strings based on PPD_MAX_TEXT.
>
> But truncated strings aren't desireable for the user; the bit chopped
> off might be the only part that differs from other strings.
>
> I think the only sane short-term approach is to adopt a policy to keep
> all translated strings under 80 bytes.

Careful with truncating UTF-8 strings!

Only plain 7-bit ASCII "just works" simple and fail-safe.
Making UTF-8 "just work" is neither simple nor fail-safe
(except "just work" means to "just abort" when there is
  any string that is not a valid UTF-8 byte sequence ;-)

If a truncated string (e.g. in a print job option value)
is no longer a valid UTF-8 byte sequence, CUPS may reject
the whole print job in "strict conformance" mode" or
CUPS may alter invalid values to some arbitrary fallback
in "relaxed conformance" mode so that the job may print
but with different printout result as what was intended.

Cf.
https://github.com/apple/cups/issues/5143
and
https://github.com/apple/cups/issues/5186


Kind Regards
Johannes Meixner
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