Enlighten me about cChunks

[LogicParrot]

We've had several people reporting crashes thanks to the PathFinder, all of them are related to cChunks.

Can someone explain what to expect and what not to expect when it comes to chunks?

• Is it safe to assume that a Tick()'s chunk is valid?
  
• Is it safe to call a_Chunk->GetNeighborChunk(a_Location.x, a_Location.z); when the chunk is invalid?
  
• Assuming a valid pointer, could a_Chunk->GetNeighborChunk(a_Location.x, a_Location.z); crash the game under some circumstances?
  
• A general explanation of the "safety instructions" of chunks would be appreciated.