system-config-printer hangs or crashes when downloading Gutenprint driver package from OpenPrinting

[Till Kamppeter]

If there is no Gutenprint package locally installed (printer-driver-gutenprint, part of standard desktop installation) and a printer supported by Gutenprint is connected to the system and set up, system-config-printer assigs the Gutenprint driver available on the OpenPrinting web site to the printer and downloads and installs it (if the user confirms on the appropriate screen). After the package is installed but still with the install progress pop-up open system-config-printer either hangs or crashes. Other driver packages get correctly installed though.

[Impact]

Users of smaller setups who have cleaned out less important packages or of server setups will run into this problem when connecting a printer only supported by Gutenprint (Canon inkjets and some Epson inkjets). Problem can also occur with other downloadable driver packages in the future.

[Test Case]

Uninstall printer-driver-gutenprint via

sudo dpkg -P printer-driver-gutenprint

If you do not have an appropriate printer, create a file named /usr/lib/cups/backend/testbackend containing the line

echo 'direct usb://EPSON/Stylus%20Photo%201290 "EPSON Stylus Photo 1290" "EPSON Stylus Photo 1290" "MFG:EPSON;CMD:ESCPL2,BDC,D4,D4PX,ESCPR2;MDL:Stylus Photo 1290;CLS:PRINTER;DES:EPSON Stylus Photo 1290;" ""'

and make it world-readable and -executable:

sudo chmod a+rx /usr/lib/cups/backend/testbackend

This emulates an Epson Stylus Photo 1290 printer on USB, at least for CUPS' printer discovery facility.

Start system-config-printer and click the "Add" button. In the printer setup wizard choose the Epson Stylus Photo 1290 under the detected printers. There will pop up "Searching driver" messages several times and in the end you will get offered to download and install the Gutenprint driver. Accept it and a progress bar pop up will appear. The progress bar will not grow during the preparing steps. Then you get asked for your password to give the admin permissions for the package installation itself. The progress bar now indicates that the package gets installed. Near the end system-config-printer either hangs or crashes. Te package is installed then

With the proposed packages for Utopic and Trusty this is fixed. The progress pop-up disappears and the wizard continues asking for the print queue name. Completing the wizard creates the queue which indeed uses the Gutenprint driver from OpenPrinting. In addition, the progress pop-up spins during the preparing steps of the installation, before the password is asked for.

[Regression Potential]

Regression potential is low, as the fix only affect the code for the package download and installation. All other parts of system-config-printer are unchanged.

[Till Kamppeter (till-kamppeter)]

Attached patch fixes the problem by simplifying the communication between system-config-printer and the install-printerdriver helper script. It is also submitted for inclusion upstream.

[Launchpad Janitor (janitor)]

This bug was fixed in the package system-config-printer - 1.5.4+20141212-0ubuntu2

---------------
system-config-printer (1.5.4+20141212-0ubuntu2) vivid; urgency=medium

  * debian/patches/35_fix-driver-package-installation-with-install-printerdriver.patch:
    Simplified communication between system-config-printer and
    install-printerdriver helper script (LP: #1412722).
  * debian/patches/37_do-not-crash-on-licensetext-being-none.patch: Crash
    guard for displaying OpenPrinting driver record where the licensetext
    field is None (LP: #1412729).
  * debian/patches/40_support-licensetext-in-separate-url.patch: Added support
    for OpenPrinting driver records with license text linked from separate
    download URL (LP: #1412729).
 -- Till Kamppeter <email address hidden> Tue, 20 Jan 2015 11:56:08 +0100

[Till Kamppeter (till-kamppeter)]

Uploaded a package fixing bug 1412729 and bug 1412722 to utopic-proposed.

[Till Kamppeter (till-kamppeter)]

Uploaded a package fixing bug 1412729 and bug 1412722 to trusty-proposed.

[Brian Murray (brian-murray)]

Hello Till, or anyone else affected,

Accepted system-config-printer into utopic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/system-config-printer/1.5.1+20141010-0ubuntu2.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Till Kamppeter (till-kamppeter)]

I have done an update of my Utopic system now and got the proposed package. Now the installation of openprinting-gutenprint works correctly, without hang or crash.

[Launchpad Janitor (janitor)]

This bug was fixed in the package system-config-printer - 1.5.1+20141010-0ubuntu2.3

---------------
system-config-printer (1.5.1+20141010-0ubuntu2.3) utopic-proposed; urgency=medium

  * debian/patches/75_fix-driver-package-installation-with-install-printerdriver.patch:
    Simplified communication between system-config-printer and
    install-printerdriver helper script (LP: #1412722).
  * debian/patches/77_do-not-crash-on-licensetext-being-none.patch: Crash
    guard for displaying OpenPrinting driver record where the licensetext
    field is None (LP: #1412729).
  * debian/patches/80_support-licensetext-in-separate-url.patch: Added support
    for OpenPrinting driver records with license text linked from separate
    download URL (LP: #1412729).
  * debian/patches/83_fix-crash-in-nextnptab-if-driver-is-zero.patch: Trivial
    patch to avoid crashes when installing downloadable printer driver
    packages via OpenPrinting. These crashes were observed via the Ubuntu
    error reporting system.
 -- Till Kamppeter <email address hidden> Tue, 20 Jan 2015 13:40:08 +0100

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for system-config-printer has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Brian Murray (brian-murray)]

Hello Till, or anyone else affected,

Accepted system-config-printer into trusty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/system-config-printer/1.4.3+20140219-0ubuntu2.6 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Till Kamppeter (till-kamppeter)]

Updated my Trusty VM with the proposed package and all works correctly now.

[Launchpad Janitor (janitor)]

This bug was fixed in the package system-config-printer - 1.4.3+20140219-0ubuntu2.6

---------------
system-config-printer (1.4.3+20140219-0ubuntu2.6) trusty-proposed; urgency=medium

  * debian/patches/43_fix-driver-package-installation-with-install-printerdriver.patch:
    Simplified communication between system-config-printer and
    install-printerdriver helper script (LP: #1412722).
  * debian/patches/45_do-not-crash-on-licensetext-being-none.patch: Crash
    guard for displaying OpenPrinting driver record where the licensetext
    field is None (LP: #1412729).
  * debian/patches/47_support-licensetext-in-separate-url.patch: Added support
    for OpenPrinting driver records with license text linked from separate
    download URL (LP: #1412729).
  * debian/patches/50_fix-crash-in-nextnptab-if-driver-is-zero.patch: Trivial
    patch to avoid crashes when installing downloadable printer driver
    packages via OpenPrinting. These crashes were observed via the Ubuntu
    error reporting system.
 -- Till Kamppeter <email address hidden> Tue, 20 Jan 2015 14:59:59 +0100