So tonight, I located an annoying bug. I have been going crazy on this for a few days. It turns out to be a vanilla bug.

 

When chunks regenerate, they don't regenerate structures properly. The issue appears to be with entities.

 

Specifically, in villages, neither villagers, nor chests in the smithy, nor lecterns in mystcraft huts, will be regenerated. Towns become ghost towns. And while I have not checked temples/pyramids/mineshaft chests/fortress blaze spawners (all of which are entities or tile entities), I do have concerns.

 

Yet if the structure file is removed, then everything is regenerated just fine.

 

So the idea: Since this appears to be some sort of vanilla bug -- when generating the chunks that have structure information, not everything gets regenerated -- perhaps forge can come up with some way to either fix this (unlikely; it would mean patching every generation routine), or else a way to remove structure entries for a chunk before regenerating that chunk (might be a simple and universal fix).

The old saying applies: If you want something done and it's simple enough, make a PR.

Though, cpw/Lex are only accepting 1.7 PRs unless it's important enough.

There is a huge difference between knowing how to code, and knowing how to set up a forge development environment and how to make a pull request.

 

And even then, this is the suggestions board, not the "here's a proposed improvement to the codebase" area.

 

Frankly, the issue gets even better with 174. Imagine regenerating chunks, finding that it's generating a hilly colored clay biome, and in the middle of the mesa there are sandstone buildings 30 or 40 meters down inside the hillside with some airgaps around the edges and the buildings themselves buried... all the more reason to wipe out the old structure data for the chunk before regenerating the chunk.