From bug-request at octave dot org Thu Dec 16 08:21:55 2004
Subject: RE: Possible Error in -ascii save/restore
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: <Hallvard dot Paulsen at wartsila dot com>
Cc: <jwe at bevo dot che dot wisc dot edu>, <bug@octave.org>
Date: Thu, 16 Dec 2004 09:22:53 -0500

On 16-Dec-2004, Hallvard dot Paulsen at wartsila dot com <Hallvard.Paulsen@wartsila.com> wrote:

| I've done a experiment, and it is likely that it is a line-termination
| error.

Yes I realize that.

| The experiment was as follows:
| $ octave
| octave:1> vect = [1, 2, 3]
| vect =
| 
|   1  2  3
| 
| octave:2> save test
| octave:3> quit
| $ dos2unix test
| test: done.
| $ octave
| octave:1> load test
| octave:2> vect
| vect =
| 
|   1  2  3
| 
| octave:3> quit
| 
| Other cygwin tools do not seam to care what type of line-termination is
| used..

I think the bug is in the octave_matrix::load_ascii function in
src/ov-re-mat.cc:

  octave_matrix::load_ascii (std::istream& is)
  {
    int mdims = 0;
    bool success = true;
    std::streampos pos = is.tellg ();

    if (extract_keyword (is, "ndims", mdims, true))
      {
	if (mdims >= 0)
	  {
	    dim_vector dv;
	    dv.resize (mdims);

	    for (int i = 0; i < mdims; i++)
	      is >> dv(i);

	    NDArray tmp(dv);
	    is >> tmp;

	    if (!is) 
	      {
		error ("load: failed to load matrix constant");
		success = false;
	      }
	    matrix = tmp;
	  }
	else
	  {
	    error ("load: failed to extract number of rows and columns");
	    success = false;
	  }
      }
    else
      {
	int nr = 0;
	int nc = 0;

	// re-read the same line again
	is.clear ();
	is.seekg (pos);

	if (extract_keyword (is, "rows", nr) && nr >= 0
	    && extract_keyword (is, "columns", nc) && nc >= 0)
	  {
	    if (nr > 0 && nc > 0)
	      {
		Matrix tmp (nr, nc);
		is >> tmp;
		if (is)
		  matrix = tmp;
		else
		  {
		    error ("load: failed to load matrix constant");
		    success = false;
		  }
	      }
	    else if (nr == 0 || nc == 0)
	      matrix = Matrix (nr, nc);
	    else
	      panic_impossible ();
	  }
	else 
	  {
	    error ("load: failed to extract number of rows and columns");
	    success = false;
	  }
      }

    return success;
  }


Note the is.tellg() and is.seekg().  I think this is failing when the
filesystem is mounted in text mode because then there is some
translation going on for CRLF pairs.  Is this a bug in Octave or the
way the Cygwin text mode filesystem works?  All we want Octave to do
here is return to the previous location in the file and read again.

jwe



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