[cmucl-help] error-handling bug

[Matt Kaufmann]

Hi --

(Sorry, I didn't easily see how to get a CMUCL Trac account; hence
this email.)

The CMUCL bug shown below occurs on 64-bit Linux, both Version 20e and
the 2014-06 snapshot.

http://common-lisp.net/project/cmucl/downloads/release/20e/cmucl-20e-x86-linux.tar.bz2
http://common-lisp.net/project/cmucl/downloads/snapshots/2014/06/cmucl-2014-06-x86-linux.tar.bz2

It appears to be the same bug as this SBCL bug (now fixed for SBCL):

https://bugs.launchpad.net/sbcl/+bug/1333327

Here is a log illustrating the bug in the CMUCL versions mentioned
above.  The expected behavior is shown later below (using SBCL 1.2.1).

.......... CMUCL 20e and also 2014-06 snapshot: ..........

* (defun read-string-fn (str)
     (handler-case
       (let ((acc nil))
         (with-input-from-string
           (stream str)
           (loop do
                 (let* ((eof-marker (cons nil nil))
                        (elem (read stream nil eof-marker)))
                   (if (eq elem eof-marker)
                       (loop-finish)
                     (push elem acc)))))
         (setq acc (nreverse acc))
         (values :OK acc))
       (error (condition)
              (return-from read-string-fn
                (values :ERROR (format nil "~A" condition))))
       (storage-condition (condition)
                          (return-from read-string-fn
                            (values :STORAGE (format nil "~A" condition))))))

READ-STRING-FN
* (read-string-fn "#\wtf")


Error in function LISP::CLOSED-FLAME:  #<String-Input Stream> is closed.
   [Condition of type SIMPLE-ERROR]

Restarts:
  0: [ABORT] Return to Top-Level.

Debug  (type H for help)

(LISP::CLOSED-FLAME #<String-Input Stream>)
Source: Error finding source: 
Error in function DEBUG::GET-FILE-TOP-LEVEL-FORM:  Source file no longer exists:
  target:code/stream.lisp.
0] 

..........

Here is the analogous log after defining the function above in SBCL
1.2.1, which I believe is as expected.

.......... SBCL 1.2.1 ..........

* (read-string-fn "#\wtf")

:ERROR
"no dispatch function defined for #\\W

  Stream: #<SB-IMPL::STRING-INPUT-STREAM {1002E27C03}>"
* 

..........

Regards,
Matt Kaufmann