[SRU] Create directories for apt configuration files if they are absent

[Nathan Teodosio]

Impact
------

The autopkgtest for 0.96.20.12, which introduces Ubuntu Pro in Xenial's software-properties, failed on Dbus tests[1].

The failure is because, at some point in time, the .keep file were removed from the otherwise empty tests/aptroot/etc/apt/apt.conf.d/. This caused the Git repository to drop tests/aptroot/etc/apt/apt.conf.d/ and also its parent, which also became empty, and the tests try to directly create files in those directories, raising the error.

It seems that previous uploaders did not use the Git checkout, as the offending commit was introduced in Jun 2019 and there were subsequent uploads that did contain those empty directories.

Test case
---------

Trigger an autopkgtest against the proposed package version. It must succeed.

Regression Potential
--------------------

Although the introduced change is idempotent, there could be other part of the code assuming the directories didn't exist and trying to create them with a "fail if already exists" approach, causing a runtime regression.

[1] https://objectstorage.prodstack5.canonical.com/swift/v1/AUTH_0f9aae918d5b4744bf7b827671c86842/autopkgtest-xenial/xenial/amd64/s/software-properties/20240301_100314_9e242@/log.gz

[Sebastien Bacher (seb128)]

I've included the bug reference to 0.96.20.13 and reuploaded (also force pushed the vcs so you might need to force pull over ubuntu/xenial)

[Launchpad Janitor (janitor)]

This bug was fixed in the package software-properties - 0.99.44

---------------
software-properties (0.99.44) noble; urgency=medium

  * Handle backup and restore of deb822 sources (LP: #2053228)

software-properties (0.99.43) noble; urgency=medium

  * Fix autopkgtest: Make sure directory exists before trying to create file
    in it (LP: #2058035).

 -- Julian Andres Klode <email address hidden> Wed, 20 Mar 2024 13:18:16 +0100

[Chris Halse Rogers (raof)]

Hello Nathan, or anyone else affected,

Accepted software-properties into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/software-properties/0.96.20.13 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 on 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, what testing has been performed on the package and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

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

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Nathan Teodosio (nteodosio)]

Autopkgtest for .13 succeeds: https://autopkgtest.ubuntu.com/results/autopkgtest-xenial/xenial/amd64/s/software-properties/20240403_080714_2ae06@/log.gz