Try to include metadata if a game is inserted when you already have all the moves #18893
Description
Example 1:
- Play 1.e4 e5 2.Bc4 Nc6 3.Qh5 Nf6 4.Qxf7.
- Go back to after 3...Nf6.
- Insert any game on lichess.
- Ideally, the metadata for the game (players, result, etc) would appear as a comment, but atm it doesn't.
Example 2:
- Run current master and play the moves mentioned in Inserting game after its first repetition #18878.
- After inputting 14...Qd6 (in this case, either staying on the position or going a move back), try inserting the Nakamura-So game.
- The game ended on this move, so no more moves get inserted. But the metadata isn't added as a comment.
This is a little tricky since the existing node could already have comments, and we don't want to overwrite it. But maybe if the node has no comments, we can update/replace the existing one?