Comparators disappearing when placed on special blocks

[Finrod_Amandil]

Hello everyone!

 

Today on our server we came across a really strange bug, and after some testing we are now very sure that the bug is caused by Forge.

 

Specs:

Game version: MC 1.12

Forge version: 14.21.1.2387

Game modifications: Usually Forge, Liteloader, Optifine, JourneyMap, DaFlight, WorldEditCUI, Multi-Hotbar, but I verified with a client that has solely Forge and no mods loaded.

Logfile: https://pastebin.com/9FMznkjA

 

Bug description:

As creative server we are trying to use as many blocks with custom textures and models as possible to achieve higher quality builds even for players with unmodded clients. Thus we are using all the Repeaters and Comparators as half slabs. As the hitbox of those is not a half block we place Cobblestone walls (hitbox 1.5 blocks) below them. We have a server-plugin which disables physics-checks on certain blocks, repeaters and comparators included, so that they are stable on blocks on which they could not be placed in vanilla Minecraft. (Pictures of how this looks ingame, with custom RP and without: http://imgur.com/a/rnrKn). Now whenever someone with a Forge-client breaks one of these slabs all adjacent slabs disappear. They should not do that and in fact on the server-side they are stable as well as on unmodded clients. Upon relogging the slabs that falsely disappeared reappear again.

 

We were able to further narrow it down to only Comparators, the bug does not occur with Repeaters. It does appear in all cases where Comparators are placed on blocks where they would not be permited in vanilla minecraft, so beside Cobble Walls also Glass, Fences and all non-solid blocks.

 

 

While very special this bug is fairly annoying for us, so if a fix could be found for this it'd be great!

 

Thanks for reading,

~ Finrod_Amandil

[Finrod_Amandil]

I can give you access to our development server, the bug is present there as well and the plugins are the same. I'll whitelist player "diesieben07", if your ingame name is a different one, please say so. IP is build.mcmiddleearth.com:55555. I should be available for the next few hours, if you'd like to have a voice chat I can offer a Discord or Teamspeak server.

 

Placing the blocks in question can be done through WorldEdit, Voxel or our custom inventory, for the latter you'd need to download our Resource Pack though.