Public bug reported:
This bug was originally reported upstream as
https://github.com/OpenPrinting/libcupsfilters/issues/29
The reporter uses Fedora 38, besides Ubuntu 23.04 the second distro
using cups-filters 2.x and libcupsfilters 2.x. As I am able to reproduce
the bug on Ubuntu 23.04 and it is a problem many users could run into
(it especially happens with driverless IPP printers) I post this bug
report as base for an SRU in 23.04.
What happens is that if a job is printed and along with it a resolution
setting is supplied which is not supported by the printer, garbage is
printed as the job gets actually rasterized with the wrong resolution.
This was discovered by the Chromium Browser sending print jobs with `-o
resolution=96dpi` regardless which resolutions the printer actually
supports. Most driverless printers receive their jobs rasterrized into
Apple Raster or PWG Raster and so for them this bug occurs.
I have already fixed the bug upstream in libcupsfilters via
https://github.com/OpenPrinting/libcupsfilters/commit/2892e9a63
The fix makes the function cfIPPAttrResolutionForPrinter() more
intensely, in which another bug showed, the list of supported
resolutions searched for as a range data type which was wrong and so the
list not being found. So I fixed this here, also in libcupsfilters:
https://github.com/OpenPrinting/libcupsfilters/commit/9ff1341c2
Now unsupported resolutions supplied to jobs are ignored so that the
default resolution gets used then.
The bug masked another bug in resolution handling which got revealed
once the above-mentioned fix was applied.Here the problem is that for
driverless IPP printers, printing in Apple Raster or PWG Raster always
the minimum resolution got used, even if I higher one was requested, as
the default resolution or by a job attribute/option which sets a higher
resolution. This I fixed in libppd via:
https://github.com/OpenPrinting/libppd/commit/e2190988ff6c1
Now always the correct resolution gets used for the rasterization of the
job and so the correct print quality obtained.
The fixes get applied to the libcupsfilters and libppd source packages
both in Mantic and in Lunar (SRU).
** Affects: libcupsfilters (Ubuntu)
Importance: High
Status: New
** Affects: libppd (Ubuntu)
Importance: High
Status: New
** Affects: libcupsfilters (Ubuntu Lunar)
Importance: High
Status: New
** Affects: libppd (Ubuntu Lunar)
Importance: High
Status: New
** Affects: libcupsfilters (Ubuntu Mantic)
Importance: High
Status: New
** Affects: libppd (Ubuntu Mantic)
Importance: High
Status: New
** Also affects: libcupsfilters (Ubuntu Mantic)
Importance: Undecided
Status: New
** Also affects: libcupsfilters (Ubuntu Lunar)
Importance: Undecided
Status: New
** Also affects: libppd (Ubuntu)
Importance: Undecided
Status: New
** Changed in: libcupsfilters (Ubuntu Lunar)
Importance: Undecided => Critical
** Changed in: libcupsfilters (Ubuntu Lunar)
Importance: Critical => High
** Changed in: libcupsfilters (Ubuntu Mantic)
Importance: Undecided => High
** Changed in: libppd (Ubuntu Lunar)
Importance: Undecided => High
** Changed in: libppd (Ubuntu Mantic)
Importance: Undecided => High
--
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Packages, which is subscribed to libcupsfilters in Ubuntu.
https://bugs.launchpad.net/bugs/2022929
Title:
Bugs in resolution handling, especially garbage printed when invalid
resolution value supplied
Status in libcupsfilters package in Ubuntu:
New
Status in libppd package in Ubuntu:
New
Status in libcupsfilters source package in Lunar:
New
Status in libppd source package in Lunar:
New
Status in libcupsfilters source package in Mantic:
New
Status in libppd source package in Mantic:
New
Bug description:
This bug was originally reported upstream as
https://github.com/OpenPrinting/libcupsfilters/issues/29
The reporter uses Fedora 38, besides Ubuntu 23.04 the second distro
using cups-filters 2.x and libcupsfilters 2.x. As I am able to
reproduce the bug on Ubuntu 23.04 and it is a problem many users could
run into (it especially happens with driverless IPP printers) I post
this bug report as base for an SRU in 23.04.
What happens is that if a job is printed and along with it a
resolution setting is supplied which is not supported by the printer,
garbage is printed as the job gets actually rasterized with the wrong
resolution. This was discovered by the Chromium Browser sending print
jobs with `-o resolution=96dpi` regardless which resolutions the
printer actually supports. Most driverless printers receive their jobs
rasterrized into Apple Raster or PWG Raster and so for them this bug
occurs.
I have already fixed the bug upstream in libcupsfilters via
https://github.com/OpenPrinting/libcupsfilters/commit/2892e9a63
The fix makes the function cfIPPAttrResolutionForPrinter() more
intensely, in which another bug showed, the list of supported
resolutions searched for as a range data type which was wrong and so
the list not being found. So I fixed this here, also in
libcupsfilters:
https://github.com/OpenPrinting/libcupsfilters/commit/9ff1341c2
Now unsupported resolutions supplied to jobs are ignored so that the
default resolution gets used then.
The bug masked another bug in resolution handling which got revealed
once the above-mentioned fix was applied.Here the problem is that for
driverless IPP printers, printing in Apple Raster or PWG Raster always
the minimum resolution got used, even if I higher one was requested,
as the default resolution or by a job attribute/option which sets a
higher resolution. This I fixed in libppd via:
https://github.com/OpenPrinting/libppd/commit/e2190988ff6c1
Now always the correct resolution gets used for the rasterization of
the job and so the correct print quality obtained.
The fixes get applied to the libcupsfilters and libppd source packages
both in Mantic and in Lunar (SRU).
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libcupsfilters/+bug/2022929/+subscriptions
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