RUN-PROGRAM encoding error leading to messed up state

[Gábor Melis]

Something similar to https://bugs.launchpad.net/sbcl/+bug/840190 still happens, although I can reproduce it only under Slime.

```
cat barf2.lisp
(defun barf ()
  (with-output-to-string (stream)
    (run-program "/usr/bin/pdfinfo"
                 '("barf.pdf")
                 :output stream)))

(defun barf2 ()
  (let ((proc (sb-ext:run-program
               "/usr/bin/pandoc"
               (list "-f" "markdown"
                     "-t" "pdf"
                     "-o" "-")
               :input :stream
               :output *standard-output*
               :wait nil))
        (ok nil))
    (unwind-protect
         (prog1
             (with-open-stream (stream (sb-ext:process-input proc))
               (format stream "hello~%"))
           (sb-ext:process-wait proc)
           (setf ok t))
      (sb-ext:process-close proc)
      (unless ok
        (sb-ext:process-kill proc -9)))))
```

Load `barf2.lisp` under Slime. Then, *in the Slime repl*,

1. evaluate `(BARF)` (should work fine)
2. evaluate `(BARF2)` (fails with `Illegal :UTF-8 character starting at byte position 10.`)
3. evaluate `(BARF2)` again and maybe get `non-empty buffer when EOF reached while reading from child`

This is not entirely deterministic, so try a couple of times. After a `non-empty buffer` error, even `(BARF)` fails with `Illegal :UTF-8`.

This is with SBCL 2.5.4.74-ddacb9c2e on Linux x86-64.

[Richard M Kreuter (kreuter)]

Is the Slime REPL's output channel bivalent? (I don't see anything in Swank that would create a bivalent SBCL stream.)

[Stas Boukarev (stassats)]

The only thing I could do to trigger an error is

(sb-ext:run-program "sbcl" '("--noinform" "--eval" "(map nil (lambda (b) (write-char #\\a *error-output*) (finish-output *error-output*) (write-byte b *standard-output*) (finish-output) ) (sb-ext:string-to-octets \"å∑ç\"))" "--quit")
                    :search t
                    :output *standard-output*)

Is your test case doing the same?

[Gábor Melis (melisgl)]

With your test case, I only got the illegal utf 8 character error from a couple of tries (restarting SBCL 4 times, running SLIME). With mine, I also get the non-empty buffer error sometimes, which is sticky (even BARF fails after it).