After much thought and mis-steps, I chose a simple solution: open another fd
for sync comms. It's almost impossible to know what state the async one is in.
jsonrpc_request_sync() is enhanced to return a valid tal object, as the current
behaviour of returning a pointer to inside an array was surprising.
Changelog-Changed: libplugin: you can now call the synchronous API functions at any time (not just in the init callback).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
bb6787df06