Rail Loader _always_ invalidates blueprint mapping about factorio-railloader

[mspielberg]

This should be taken care of by the if not next(railloader_chests) check, which returns from the function early.

Ok, figured it out (with a lot more logging statements). It's not your rail loader, but the blueprinting. When reusing a blueprint (blue "Select new contents" button), the blueprint retrieved from player.blueprint_to_setup isn't valid_for_read and the blueprint retrieved via player.cursor_stack is missing the blueprint entities (bp.get_blueprint_entities() returns nil).

This may be a bug in the main game... Will make a post on the forum about it, as this hurts mods like yours that need to either replace entities, or store data in tags.

[mspielberg]

Problems with "Select new contents" is a known bug with significant impact and no projected fix: https://forums.factorio.com/88100
The on_gui_closed logic in BRL should work around the bug as long as the blueprint being updated is a character inventory, and not in the blueprint library.

Yea, mk-fg sent me that link last night. I need to learn to not be soo specific in my search terms, otherwise I would've had that one in my search results (I used "reuse" instead of "new contents" in search).

You'd think it'd be trivial to drop the reference into player.blueprint_to_setup during the event.

[mspielberg]

The blueprint library throws a wrench into everything. Blueprints living in the library are not real items, so they don't behave correctly when in the cursor, can't have a reference to them passed into events, can't be inspected or modified from a quickbar slot, etc.