id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	difficulty
1801	parley constructs an internally inconsistent input port	Vasilij Schneidermann		"The parley egg still hasn't been ported successfully to C5. Most of the steps are done already (egg file, imports, tests), but interactive usage fails:

{{{
#;2> (define p (let ((old (current-input-port))) (make-parley-port old)))
#;3> p
#<port ""(parley)"">
#;4> (input-port? (current-input-port))
#t
#;5> (input-port? p)
#t
#;6> (current-input-port p)

Error: (current-input-port) bad argument type - not a port of the correct type: #<port ""(parley)"">

        Call history:

        <syntax>          (current-input-port p)
        <eval>    (current-input-port p)        <--
}}}

Looking at the code performing checks, it seems that the I/O direction slot is checked whether it's an input one. Both `input-port?` and `current-input-port` seem to look at the same slot, but arrive to different conclusions. Perhaps C5 changed some port internals?

One way of side-stepping this would be to avoid low-level port construction, but this might break C4 compatibility completely."	defect	new	minor	someday	extensions	5.3.0		parley port	Christian Kellermann	trivial