Re: strcat error on printing plots

[Marco Atzeri]

--- Mar 21/7/09, John W. Eaton <address@hidden> ha scritto:

> Da: John W. Eaton <address@hidden>
> Oggetto: Re: strcat error on printing plots
> A: "Marco Atzeri" <address@hidden>
> Cc: "Ben Abbott" <address@hidden>, "octave maintainers list" <address@hidden>
> Data: Martedì 21 luglio 2009, 16:35
> On 21-Jul-2009, Marco Atzeri wrote:
> 
> | unfortunately no change:
> | 
> |
> *********************************************************
> | error: Invalid call to strcat.  Correct usage is:
> | 
> |  -- Function File:  strcat (S1, S2, ...)
> | 
> | 
> | Additional help for built-in functions and operators is
> | available in the on-line version of the manual.  Use
> the command
> | `doc <topic>' to search the manual index.
> | 
> | Help and information about Octave is also available on
> the WWW
> | at http://www..octave.org and via the address@hidden
> | mailing list.
> | warning: __gnuplot_get_var__: some elements in list of
> return values are undefined
> |
> ***************************************************************
> 
> Try
> 
>   debug_on_error (true);
>

strange, now I have also errors before the crash on plot

octave:1>debug_on_error(true);                                   octave:2> 
a="prova.png";
octave:3> x=1:100;
octave:4> plot (x,x);
keyboard: stopped in /usr/share/octave/3.2.0/m/plot/newplot.m
debug> dbstack()
keyboard: stopped in /usr/share/octave/3.2.0/m/plot/newplot.m
Stopped in:

--> newplot at line 47 column 2
    plot at line 183 column 5
debug> dbcont()
octave:5> print( "prova1.png","-dpng");
keyboard: stopped in /usr/share/octave/3.2.0/m/plot/print.m
debug> dbstack()
Stopped in:

--> print at line 514 column 7
debug> dbcont()
......

octave:10> print( "prova1.png","-dpng");
error: Invalid call to strcat.  Correct usage is:

 -- Function File:  strcat (S1, S2, ...)


Additional help for built-in functions and operators is
available in the on-line version of the manual.  Use the command
`doc <topic>' to search the manual index.

Help and information about Octave is also available on the WWW
at http://www.octave.org and via the address@hidden
mailing list.
error: called from
    print_usage at line 64 column 3
    strcat at line 110 column 5
    __gnuplot_get_var__ at line 113 column 11
    __go_draw_axes__ at line 39 column 18
    __go_draw_figure__ at line 82 column 1
    gnuplot_drawnow at line 88 column 5
keyboard: stopped in /usr/share/octave/3.2.0/m/help/print_usage.m

this is the     __gnuplot_get_var__

      ## Now read from fifo.
      reading = true;
      str = {};
      while (reading)
        str{end+1} = fgets (gpin);
        if (isnumeric (str{end}) && (str{end} == -1))
          reading = false;
          str = str(1:(end-1));
        endif
      endwhile
      str = strcat (str{:});            <- line 113
      fclose (gpin);

so eventually is a fifo issue communicating with
gnuplot.
Not really surprising as the MS implementation
that is used to built the cygwin function
is buggy
http://cygwin.com/ml/cygwin/2009-07/threads.html#00233

> 
> jwe
> 

thanks for the hint.
I will try to put a temporary workaround 
around strcat to avoid the crash.

Marco