Sometimes shader files clone their content from other shader files

[applejuiceyy]

Nature of issue?

• Found a bug

Details about the bug:

• Web browser and version: Firefox Developer (90.0b12 (64-bit))
• Operating System: Windows 10
• Steps to reproduce this bug:

(I don't really know how to describe this hence the weird title)

[JetStarBlues]

This might be related to what I encountered #1887