OK, I see it now. I unjustly assumed that the appearence of the target highlights meant it could move. But the problem manifests itself only after selecting the destination. It seems to think that leaving the rank is another promotion opportunity, because again the 'click on piece of choice' message appears, and Prince and Queen get highlighted in the table. But it is halfhearted about it; if I click in the table nothing happens.
This is a bug in the Diagram script, but it also raises the question how a fix would have to look. If this were Shogi, leaving the zone would llow the promotion, and if it were Chu Shogi leaving it with a capture would allow it. But Diagrams for those would have a promoOffset defined for calculating the promoted type. I suppose that for Chesslike promotions it should only promote when entering the zone? Not when moving inside it, or leaving it?
OK, I see it now. I unjustly assumed that the appearence of the target highlights meant it could move. But the problem manifests itself only after selecting the destination. It seems to think that leaving the rank is another promotion opportunity, because again the 'click on piece of choice' message appears, and Prince and Queen get highlighted in the table. But it is halfhearted about it; if I click in the table nothing happens.
This is a bug in the Diagram script, but it also raises the question how a fix would have to look. If this were Shogi, leaving the zone would llow the promotion, and if it were Chu Shogi leaving it with a capture would allow it. But Diagrams for those would have a promoOffset defined for calculating the promoted type. I suppose that for Chesslike promotions it should only promote when entering the zone? Not when moving inside it, or leaving it?