TEXTUREx lump stacking

[nstlaurent]

Started with this wad:
https://www.doomworld.com/forum/topic/153336-pdelivry-phobos-delivery-now-available-on-idgames/

Defines TEXTURE1 with only SKY1, SKY2, and SKY3.

This works in GZDoom, Crispy, Edge Classic where these textures are applied on top of the IWADS TEXTURE1.

Boom based ports, Kex, Helion, and Odamex, will override the IWAD TEXTURE1 lump from the PWAD which results in missing textures.

[thecnoNSMB]

What's the vanilla exe behavior in this case, if I may ask?

[nstlaurent]

They don't stack. It would load TEXTURE1 from the PWAD only which would result in missing textures in this case.