OpenPrinting Mini Summit at IIT Mandi, India
On November 9 we had a meeting in India presenting the work of OpenPrinting at one of the universities where our Google Summer of Code students came from.
See our separate news article with pictures.
Google Summer of Code 2020
We need to start with the student selection process soon, so that we can let them do assignments to compensate for the missed Google Code-In opportunity.
The mentoring organization application time window for the Google Summer of Code 2010 got announced. It is from January 14th to February 5th, 2020.
Avahi local service support
This has raised the idea in me to make cups-filters (cups-browsed and the “driverless” utility) use DNS-SD-service-name-based IPP URIs, like CUPS does. Compared to the standard host-name-based ones they are independent of network interfaces and ports and so make it easier to implement local IPP services (like Printer Applications). I have implemented this in cups-filters 1.26.0 (see below).
We urgently need the localhost support for the Printer/Scanner Applications, as PPD support will go away within a year.
OpenPrinting web site
Dheeraj has continued to work on the web site and fixed several issues. Especially the last three news items are presented on the front page now and they are listed with author and date. On the “News and Events” page we have also a link to the archive of minutes of the monthly OpenPrinting phone meetings now.
CUPS 2.3.1 got released today!
Tons of bug fixes:
Changes in CUPS v2.3.1 ---------------------- - Documentation updates (Issue #5661, #5674, #5682) - CVE-2019-2228: The `ippSetValuetag` function did not validate the default language value. - Fixed a crash bug in the web interface (Issue #5621) - The PPD cache code now looks up page sizes using their dimensions (Issue #5633) - PPD files containing "custom" option keywords did not work (Issue #5639) - Added a workaround for the scheduler's systemd support (Issue #5640) - On Windows, TLS certificates generated on February 29 would likely fail (Issue #5643) - Added a DigestOptions directive for the `client.conf` file to control whether MD5-based Digest authentication is allowed (Issue #5647) - Fixed a bug in the handling of printer resource files (Issue #5652) - The libusb-based USB backend now reports an error when the distribution permissions are wrong (Issue #5658) - Added paint can labels to Dymo driver (Issue #5662) - The `ippeveprinter` program now supports authentication (Issue #5665) - The `ippeveprinter` program now advertises DNS-SD services on the correct interfaces, and provides a way to turn them off (Issue #5666) - The `--with-dbusdir` option was ignored by the configure script (Issue #5671) - Sandboxed applications were not able to get the default printer (Issue #5676) - Log file access controls were not preserved by `cupsctl` (Issue #5677) - Default printers set with `lpoptions` did not work in all cases (Issue #5681, Issue #5683, Issue #5684) - Fixed an error in the jobs web interface template (Issue #5694) - Fixed an off-by-one error in `ippEnumString` (Issue #5695) - Fixed some new compiler warnings (Issue #5700) - Fixed a few issues with the Apple Raster support (rdar://55301114) - The IPP backend did not detect all cases where a job should be retried using a raster format (rdar://56021091) - Fixed spelling of "fold-accordion". - Fixed the default common name for TLS certificates used by `ippeveprinter`. - Fixed the option names used for IPP Everywhere finishing options. - Added support for the second roll of the DYMO Twin/DUO label printers.
Currently released is 1.26.0.
This release adds some new features to cups-browsed and to the driverless utility: Both now use DNS-SD-service-name-based URIs for IPP print queues, like CUPS does. These URis are independent of network interfaces and ports and so make providing IPP services on the local machine (Printer Applications) easier. cups-browsed creates large numbers of local queues in portions now, so that it can treat jobs to print clusters between the portions, this makes printing more reliable in large networks with many printers. In addition, a lot of bugs got fixed.
Bug fix release, mainly to solve problems of cups-browsed, mainly for compatibility problems with some printers, leaks, and crashes. Also updated the PPD generator to catch up with the one of CUPS. Prefer Apple Raster instead of PWG Raster as some printers have bugs in their PWG Raster implementation.
Bug fix release, to address a bug of grayscale jobs not printed on PostScript printers when Poppler is used as PDF interpreter, to allow printing on printers which claim to accept PWG Raster but actually do not print this format, and to eliminate all compiler warnings when building the package.
CHANGES IN V1.26.0 - cups-browsed: When generating local queues for printers for which the local CUPS daemon would provide temporary queues use the PPDs generated by libcupsfilters and not the ones generated by CUPS. The PPD generation of libcupsfilters also works with IPP-1.x-only printers, printers which do not support to query "media-col-database" and printers which support driverless printing only via PCLm. This can be changed via the "UseCUPSGeneratedPPDs" directive in cups-browsed.conf (Issue #22). - libcupsfilters: Re-structured the get_printer_attributes() function to remove the recursive calls for the fallbacks, to check required attributes in the response only if requested, and to fully integrate the method of getting a suitable response for a full printer capability list also if the printer is only IPP 1.1 or does not support the "media-col-database" attribute (Issue #22, Issue #163). - libcupsfilters, cups-browsed, driverless: Moved the funtions get_printer_attributes() and resolve_uri() from cups-browsed into libcupsfilters, to share them with the driverless utility (Issue #22). - implicitclass: Fixed wrong stdout redirection from the filters to the IPP backend and hard-coded path for "ipp" backend call (Possible fix for Issue #163, Issue #181). - cups-browsed, driverless: Use DNS-SD-service-name-based URIs instead of host-name-based ones, as CUPS also does. In cups-browsed one can switch back to the conventional host-name-based URIs via the new "DNSSDBasedDeviceURIs" configuration option. Note that cups-browsed always uses conventional URIs for printers discovered via legacy CUPS browsing or LDAP. - cups-browsed: When removing a CUPS queue, do not consider an error (and retry) if the queue does not actually exist. Also ignore errors when checking whether there are still jobs. This way when a new queue gets created and the generation of the PPD file fails the attempt to remove this non-existing queueu when removing the printer entry does not cause any problem. - cups-browsed: Improved the fallback mechanism of the get_printer_attributes() function. Instead of considering the request failed by the content of the response only when not more than the two language atrributes come out, we check through a list of required attributes whether they are all there. In addition, we actually fail when all callbacks have failed (Issue #22). - cups-browsed: Introduced new configuration options "UpdateCUPSQueuesMaxPerCall" and "PauseBetweenCUPSQueueUpdates" to limit the amount of local CUPS queues created, modified, or removed in a single event callback. Before, when there were thousands of printers in the network, cups-browsed got blocked for other tasks, like assigning a destination printer for a cluster print job (Issue #163). CHANGES IN V1.25.13 - implicitclass: When passing on the job via the "ipp" CUPS backend, set argv to the destination printer URI (Pull request #173). - cups-browsed: Added another fallback to the get-printer-attributes IPP request: Now after failing the standard request ("all", "media-col-database") with both IPP 2.0 and IPP 1.1, try simply "all", without "media-col-database" (Pull request #173). - cups-browsed: Do not set printer-is-shared for remote CUPS queue when making a temporary queue permanent (Pull request #180). - cups-browsed: Fix leaks of ipp_t struct and load balancing on the servers (Pull request #179). - cups-browsed, implicitclass: Prioritize Apple Raster against PWG Raster when selecting the PDL for the destination printer for a job sent to a cluster, also cleaned up the PDL selector code and added PostScript support. - libcupsfilters: Updated the PPD generator adding all changes of the PPD generator of CUPS: Support for "job-account-id", "job-accounting-user-id", "job-password", finishing options "trim-..." added, finishing options and "finishing-col-database" support synced with CUPS. - libcupsfilters: In the PPD generator get the mode for handling the back sides of the sheets when printing duplex preferrably from the "urf-supported" attribute. - libcupsfilters: Fixed bug that the PPD generator did not output the "*CloseUI: *ColorModel" line when it did not determine a default setting for "ColorModel". - cups-browsed: Added some missing memory allocations leading to a segfault (Issue #175). CHANGES IN V1.25.12 - libcupsfilters: Use the text names "Draft", "Normal", and "High" instead of 3, 4, and 5 as choice names for the "cupsPrintQuality" option as CUPS does (Issue #171). - libcupsfilters: If a printer supports both Apple Raster and PWG Raster let the generated PPD use Apple Raster as there are several printers which report PWG Raster support but do not actually print PWG Raster (Pull reguest #168, Issue #171, CUPS issue #5238). - cups-browsed: Fix unset location check to use DNS-SD field (Pull request #172). - libcupsfilters, beh, implicitclass, foomatic-rip, imagetopdf, mupdftoraster, pdftops, sys5ippprinter, cups-browsed, driverless: Silenced all compiler warnings to make the build process of cups-filters completely free of warnings. - pdftops: Fixed crash when using filter without PPD file. - pdftops: If printing grayscale jobs with Ghostscript as PDF renderer, add "-sProcessColorModel=DeviceGray" to Ghostscript command line. - pdftops: Do not use the ugly "pdftops -level1 ..." workaround to get grayscale PostScript output from Poppler. It leads to huge output files with Poppler's "pdftops" utility and does not work at all with "pdftocairo". Poppler itself does not support PostScript output converted to grayscale. Issue a warning with the hint to use Ghostscript or MuPDF as PDF renderer (Issue #169). - libcupsfilters: In the cupsRasterParseIPPOptions() accept also "Mono", "Monochrome", and "Gray" as color space names.
No further news.