Test buffered valid message
Test buffered valid message

A message can be broken across two buffers, with the split inside its
header.  Usually this will occur when sending many messages, such that
the first buffer fills.

This test uses the RPC to verify that the message is actually being
received in two pieces.

There is a very rare chance of a race condition where the test framework
sends a message in between the two halves of the message under test.  In
this case the peer will almost certainly disconnect and the test will
fail.  An assert has been added to help debugging that rare case.


Former-commit-id: 042b2fbf2873f3ff0824df8dfa47284d5d563f7a
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin