[Octave-bug-tracker] [bug #43036] popen2 on Windows fails quietly if command writes to stderr

[Colin Macdonald]

URL:
  <http://savannah.gnu.org/bugs/?43036>

                 Summary: popen2 on Windows fails quietly if command writes to
stderr
                 Project: GNU Octave
            Submitted by: cbm
            Submitted on: Wed 20 Aug 2014 10:13:23 PM GMT
                Category: Interpreter
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: None
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.8.1
        Operating System: Microsoft Windows

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Details:

If a popen2 subprocess every outputs to stderr, octave can't read any more
from its stdout.

I'll attach two files.  The .m file does popen2() on the .bat file.  The .bat
file echos to stdout several times, then once to stderr.  Subsequent stdout
never makes it back to Octave.

I've tested this on MXE.  Its not clear to me whether this runs the
"roll-your-own" popen2 from lo-sysdep.cc or something else.

I'm not easily able to test more recent versions (well, probably 3.8.2),
although let me know if not reproducible and I'll see what I can do.  (I don't
have any admin rights on the windows box, its called something like "Windows
2008 Server" if that's relevant).

On a personal note: I'm rather proud of myself for isolating this.  Working on
Windows feels like building lego models in the dark with marshmallows instead
of fingers!




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File Attachments:


-------------------------------------------------------
Date: Wed 20 Aug 2014 10:13:23 PM GMT  Name: popen2_bug.m  Size: 784B   By:
cbm

<http://savannah.gnu.org/bugs/download.php?file_id=31928>
-------------------------------------------------------
Date: Wed 20 Aug 2014 10:13:23 PM GMT  Name: echo_bug.bat  Size: 547B   By:
cbm

<http://savannah.gnu.org/bugs/download.php?file_id=31929>

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