Incorrect size of converted patches (Heretic sky)

[ETTiNGRiNDER]

SLADE Version: 3.1.1.8 Operating System: Windows

Issue Details: When converting a 256x200 graphic to a patch for a Heretic sky, the lump produced comes out to be 54536 bytes, while a correctly converted Heretic sky patch should be exactly 53512 bytes. This causes visible tutti-frutti errors in vanilla/chocolate. This seems to be a regression as older versions of SLADE (checked against v3.1.1.5) convert the patch correctly.

Further info/example can be found here: https://www.doomworld.com/forum/topic/110813-skybox-problem-in-heretic/

[Gaerzi]

It's not incorrect, it's the consequence of a change made for making tall graphics compatible with vanilla engines, except of course that Heretic had to use some godawful hacks for its tall sky textures, godawful hacks that aren't compatible with the normal way of making vanilla tall patches.

The solution would be to make the change from 015116a8da7ec175c0fa2d11f943de65fbe32799 conditional, presumably on a user option.