2 items about fltk backend

[Michael D. Godfrey]

I have discovered:

1. The problem of no data appearing when a plot command
    such as plot([1:200]) was issued came back on my system.
    I tried running glxgears to see if X11 was OK.  It ran. I
    retried the Octave plot([1:200]) and it worked.  This has
    happened several times more (while I was working on
    problem 2 below) so it is definitely a reliable connection.
    This means that something that Octave does to openGL and
    X11 gets them confused.  Whatever glxgears does straightens
    them out.  Ugh.

2. I tried with fltk backend set:
    plot([1:200])
    print  "test.pdf"

    This fails do to gs not finding the /tmp/xxx.ps  file which
    print.m should have written.  The reason for this is a timing
    window in print.m.  The window does not seem to cause gnuplot
    usage to fail, but it is still, I think, unsafe.  fltk takes longer
    to produce the .ps, so it fails all the time.  My kludge fix was to
   insert  at line 692  (approx)
        while(!exist(name))
        pause(5);
      endwhile;
The next line after this should be:
      [errcode, output] = system (command);

This fixes the problem, but is not a fix suitable for inclusion
in the code.  There should be a way of determining if draw_now()
has actually completed and generated its output.  Testing on this
completion is what should go in place of my patch, I think.

If someone knows the right way to do this, could the generate the
changeset, or tell me how?

Michael