Fix null displayname crash as described in #21885

[TomG736]

As discussed in #21885, displayname is sometimes Null when updating from older versions. This pull requests adds the code suggested in that issue by @dh-connect with modifications suggested by @kbzowski

[skjnldsv]

@TomG736 what is the status? :)

[Alekzanther]

@rullzer This issue has been plaguing me (and many others) for a long time... It breaks large sections of Nextcloud. What's happening here? Isn't @TomG736:s fix good enough for now? Or are we missing something?

@jospoortvliet do you know?

[PVince81]

@TomG736 can you rebase ?

If the fix as-is has already proven to work for many people in #21885 maybe we can take it as is ?

[TomG736]

Rebased back off current master

[PVince81]

Oracle fails:

1) Test\User\DatabaseTest::testSearch
Failed asserting that actual size 3 matches expected size 2.

/home/runner/work/server/server/tests/lib/User/Backend.php:114
/home/runner/work/server/server/tests/lib/User/DatabaseTest.php:125

Looks slightly related, but not sure

[PVince81]

looking closer, if the search finds 3 users containing "bar" instead of 2, maybe there's some random cleanup issue in the tests, likely unrelated. I'll restart the tests just in case...

[Alekzanther]

looking closer, if the search finds 3 users containing "bar" instead of 2, maybe there's some random cleanup issue in the tests, likely unrelated. I'll restart the tests just in case...

Did it work? There seems to be some "requested changes" (that don't really need to be addressed) blocking merge?

[MorrisJobke]

Makes sense 👍

[welcome]

Thanks for your first pull request and welcome to the community! Feel free to keep them coming! If you are looking for issues to tackle then have a look at this selection: https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22

[szaimen]

backport for stable21?

[SyZn]

backport for stable21?

Hi,
A backport would be greatly appreciated. I run into this issue on every update since NC 19 and had to fix it manually each time.

[blizzz]

/backport to stable22

[blizzz]

/backport to stable21

[blizzz]

/backport to stable20

[backportbot-nextcloud]

The backport to stable22 failed. Please do this backport manually.

[szaimen]

/backport to stable22

[backportbot-nextcloud]

The backport to stable22 failed. Please do this backport manually.

[szaimen]

backprt to stable22 fails because it is already included in stable22

[blizzz]

backprt to stable22 fails because it is already included in stable22

makes sense :)