[SciPy-Dev] github: disappearing comments - clarification?

[josef.pktd at gmail.com]

A question for the github experts:

Under what scenarios do comments on github pull requests disappear?

I've never seen a clear answer just my speculation. (based on: Did it
disappear or is my search fu insufficient?)

For example, some comments disappear after a rebased force push. all
comments or just inline code comments?
If a pull request never gets merged and the originating branch is
deleted, do the comments also disappear?

any other cases of disappearing comments?

Thanks,

Josef