[2.0.51] Unmodifiable modded blueprint prompts to save

[Gergely]

TLDR: Attempting to close a blueprint preview with modded content, without having the mod enabled results in a "save modifications" prompt.

Steps to reproduce

• Put a blueprint in the blueprint library that contains space age content
• Turn off space age mods
• Enter a map and open the blueprint library
• Open the blueprint preview
• Close the preview by either pressing Esc or the close button. (Pressing E would save, and therefore works as expected.)

Expected

Blueprint preview closes

Actual

Game prompts about saving blueprint modifications, even though the blueprint is unmodifiable.
(This does not happen if the steps are performed on an unmodded blueprint.)

Further notes

A blueprint can be unmodifiable even if only the icons contain unknown items. However, selecting new content for the blueprint causes everything to be modifiable, while still having an unknown item as an icon. Inconsistent? Perhaps allowing modifications if only icons contain unknown items could be considered.

[Rseding91]

Thanks for the report. Can you provide a save file that shows this issue? When I test it, I don't have the "modified" prompt.

[Gergely]

Here is a save file.

My reproduction steps:

• Open save in base game factorio (space age, quality and elevated rail mods should be off)
• Open game blueprints
• Right click any of the blueprints to open preview
• Press Esc

The prompt to save modifications should show up.

[Rseding91]

Thanks for the save. This is now fixed for the next release.