This is for almost any Minecraft Java version.
It is only the blockstates that do this. It really bothered me that default fences aren't automatically like this. All wood fence types get as long as the fence.
Bamboo and nether brick fences are not affected (please tell me if you want them to be)
I hope you enjoy this resourcepack.
Please report any problems with the resourcepack or any mod support requests.
For compatibility with other resource packs you may need to delete the files of the pack in models/block and modify the fence post models in your other pack to fix culling issues. For packs that have change blockstates from vanilla, it may not work without tinkering.
Non Bamboo version: https://modrinth.com/resourcepack/sc-long-fences-(no-bamboo)/settings/description
Nether Brick Fence version https://modrinth.com/resourcepack/sc-long-nether-brick-fence