[armedbear-ticket] [armedbear] #342: missing default method for gray-streams:stream-finish-output

[armedbear]

#342: missing default method for gray-streams:stream-finish-output
------------------------+-----------------------
 Reporter:  avodonosov  |      Owner:
     Type:  defect      |     Status:  new
 Priority:  major       |  Milestone:
Component:  streams     |    Version:  1.3.0-dev
 Keywords:              |
------------------------+-----------------------
 Test case:

 {{{
 (ql:quickload :flexi-streams)

 (let* ((binary-stream (flexi-streams:make-in-memory-output-stream)))
   (finish-output binary-stream))

 The value #<FLEXI-STREAMS::VECTOR-OUTPUT-STREAM {1E566F3}> is not of type
 #<STANDARD-CLASS FLEXI-STREAMS:FLEXI-OUTPUT-STREAM {7D84CE}>.
    [Condition of type SIMPLE-TYPE-ERROR]

 Backtrace:
   0: (#<FUNCTION {1C9E6C0}> #<SIMPLE-TYPE-ERROR {FC82A6}> #<FUNCTION
 {1C9E6C0}>)
   1: (APPLY #<FUNCTION {1C9E6C0}> (#<SIMPLE-TYPE-ERROR {FC82A6}>
 #<FUNCTION {1C9E6C0}>))
   2: (SYSTEM::RUN-HOOK SYSTEM::*INVOKE-DEBUGGER-HOOK* #<SIMPLE-TYPE-ERROR
 {FC82A6}> #<FUNCTION {1C9E6C0}>)
   3: (INVOKE-DEBUGGER #<SIMPLE-TYPE-ERROR {FC82A6}>)
   4: (GRAY-STREAMS:STREAM-FINISH-OUTPUT #<FLEXI-STREAMS::VECTOR-OUTPUT-
 STREAM {1E566F3}>)
   5: (SYSTEM::%FINISH-OUTPUT #<FLEXI-STREAMS::VECTOR-OUTPUT-STREAM
 {1E566F3}>)
   6: (FINISH-OUTPUT #<FLEXI-STREAMS::VECTOR-OUTPUT-STREAM {1E566F3}>)

 }}}

 This happens because there is no default method for stream-finish-output.
 According to the Gray proposal, default method should exist and do
 nothing.

 The fix:
 {{{
 Index: src/org/armedbear/lisp/gray-streams.lisp
 ===================================================================
 --- src/org/armedbear/lisp/gray-streams.lisp    (revision 14464)
 +++ src/org/armedbear/lisp/gray-streams.lisp    (working copy)
 @@ -314,6 +314,10 @@
    (declare (ignore stream))
    nil)

 +(defmethod stream-finish-output (stream)
 +  (declare (ignore stream))
 +  nil)
 +
  (defmethod stream-clear-output (stream)
    (declare (ignore stream))
    nil)
 }}}

 Also, ABCL handles the absence of default method not very correctly.
 It should signal "no applicable method". What happens here is that flexi-
 streams overrides
 stream-finish-output for one of its classes - FLEXI-STREAMS:FLEXI-OUTPUT-
 STREAM.
 So, I think ABCL sees that there is only one variant of method,
 and tries to apply this method, despite we pass object of another class.
 And here typecast happen.

--
Ticket URL: <http://abcl.org/trac/ticket/342>
armedbear <http://abcl.org>
armedbear