Fixed a bug that prevented the display of multiple empty playlists

[dustdfg]

What is it?

• Bugfix (user facing)

Description of the changes in your PR

Turned out this bug was already fixed two years ago but unfortunately
it made its way back again. It was solved in #9642 but back then another
method was used for querying playlists from db (for add playlist dialog) then in
ef4a623 was introduced another method
which had the same problem as fixed in #9642 and which eventually replaced
original method in code for querying playlists from db (for add playlist dialog)

Fixes the following issue(s)

• Fixes Only one empty playlist is shown #2758

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.
• The proposed changes follow the AI policy.
• [*] I tested the changes using an emulator or a physical device.

[dustdfg]

@Stypox Hello! Look at it e44d092 seems like my PR remades change which was already merge long time ago but for some reason was then reverted.... So bug was reintroduced. What would you say? I wanted to find who made that SQL but found that years ago someone already did what I did in this PR and that it was merged (by you)...

So it means that change itself not containing mistake? PR and commit are formatted bad but they could be just changed to "reintroduce "?

[dustdfg]

@Stypox Sorry first description was not accurate. I a bit messed up methods. Firstly there was only one method which was used for querying playlists. But then in ef4a623 you added new similar method but with old mistake and then overtime the second method was used...

[TobiGr]

We should add a comment so that this is not reverted again

[dustdfg]

We should add a comment so that this is not reverted again

The only note I can imagine is to just copy description of #9642, modify to accommodate current state and put it as comment inside file. Something like:

If a playlist has no streams, there won’t be any rows in the playlist_stream_join table that have a foreign key to that playlist. Thus, the playlist_id will not have a corresponding value in any rows of the join table. So, if you group by the playlist_id, only playlists that contain videos are grouped and displayed. Look at #9642 #13055

Is that sufficient?

[TobiGr]

thank you!