fix cue preview

[daschuer]

Cue preview can latch undesired, due to a race condition.
This is fixed here (lhttps://bugs.launchpad.net/mixxx/+bug/1903002)

[Holzhaus]

It seems to work, my short manual test was unable to reproduce the issue. The play button does not light up during previewing. I don't really care about it, but maybe someone would like to keep that?

[daschuer]

Ah, I see.
It looks like we need to do much more.
I will have s look.

[Holzhaus]

Ah, I see.
It looks like we need to do much more.
I will have s look.

Shall we merge this anyway? I'd consider the play button issue less severe than the broken previewing.

[daschuer]

Yes, we can go in small steps.

[daschuer]

I can't reproduce the play button issue. Does it always happen? With this branch or merged to main?

[Holzhaus]

I can't reproduce the play button issue. Does it always happen? With this branch or merged to main?

Yes, always. Using this branch directly.

[daschuer]

This is actually an issue with the 2.3 branch.
The play button must not be permanent lit during preview.
This was the case with the 2.2 branch and is not altered by this branch.
So this is ready to merge.

[Holzhaus]

Ok

[ronso0]

The play button must not be permanent lit during preview.

You mean: the play doesn't necessarily need to be lit while previewing.
Yet I think a Play button highlight while previewing does give a hint that pressing play would make the deck keep playing after preview release.