[zeromq-dev] Does ZMQ handle tcp-RST?

[Pieter Hintjens]

HWM=0 does not mean there's no buffering. The TCP buffers will accept
messages up to a certain size. If you try with larger messages send()
may behave differently with HWM=0. Also, the queuing strategy depends
on the socket type.

Can you find a specification somewhere that states what should happen
in this case, and can you make a test case that proves the software is
not conforming to the specification? That is a bug. "I am trying edge
cases and don't understand the results" isn't a bug.

So read the specs (there are RFCs for socket behavior, and man pages)
carefully and try to make minimal test cases to disprove the code.