Puzzles for certain openings do not show side selection control

[C-Higgins]

Example URL: https://lichess.org/training/Englund_Gambit_Complex

lila/ui/puzzle/src/view/theme.ts

Line 42 in be7cb33

: !data.replay && !ctrl.streak && angle.opening && renderColorForm(ctrl),

The side selection control is not rendered because angle.opening is false. This is apparently not an "opening", but a "theme". I'm not sure what the distinction is, but there's no reason these can't be filtered by color. In fact, changing the URL to include the color does work:

• https://lichess.org/training/Englund_Gambit_Complex/white
• https://lichess.org/training/Englund_Gambit_Complex/black

Since this feature is fully supported in the URL, the UI control should not be hidden based on angle.opening.

[ornicar]

It makes sense to select a color when, and only when, we're training a given opening.

[C-Higgins]

You don't think Englund Gambit Complex is something people might want to train for their openings?

[ornicar]

I see, that's just the opening naming being weird and inconsistent.

"Englund Gambit Complex" doesn't exist, it's not a chess position. There exist named openings that include it in their name, such as Englund Gambit Complex: Felbecker Gambit or even more confusingly Englund Gambit Complex: Englund Gambit.

But "Englund Gambit Complex" is not a thing and should therefore not have any puzzles associated to it.

[C-Higgins]

Thanks for the swift turnaround! 🙏