bug#54458: 27.2; erc-dcc-get: Re-entering top level after C stack overflow

[Mattias Engdegård]

27 mars 2022 kl. 22.54 skrev Mattias Engdegård <mattiase@acm.org>:

> Not sure where this happens but it looks like it might be erc-dcc-send-filter.

Some additional notes:

This is not an infinite recursion; eventually the stack will culminate and 
recede, unless (as in this case) we run out of room first.

In Emacs 29 the byte-code engine is more stack-efficient but that just means 
that bigger files can be transferred without a stack overflow. The bug is still 
there.

Presumably we should add a note to the documentation of process filter 
functions that they shouldn't be used to send more data to the process. (Not 
sure what to recommend, an idle timer maybe?)

I'm not going to fix this because I don't know ERC very well and wouldn't be 
able to test it sufficiently, but our ERC maintainers do and can!