From bug-octave-request at bevo dot che dot wisc dot edu Tue Dec 17 17:27:38 2002
Subject: Unidentified subject!
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Johannes Martin <jmartin at beaker dot sowi dot uni-mainz dot de>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Tue, 17 Dec 2002 17:27:01 -0600

On 17-Dec-2002, Johannes Martin <jmartin at beaker dot sowi dot uni-mainz dot de> wrote:

| To: bug-octave at bevo dot che dot wisc dot edu
| Cc: jmartin
| Subject: fprintf() aborts with error message
| 
| Bug report for Octave 2.1.36 configured for i686-pc-linux-gnu
| 
| Description:
| -----------
| 
|   fprintf("") fails with error message
| 
| Repeat-By:
| ---------
| 
| 	octave:1> fprintf("")
| 	error: fprintf: internal error handling format
|   Expected behaviour (Octave 2.0.16.92)
| 	octave:3> fprintf("")
| 	ans = -1
| 
|   This is still true for Octave 2.1.40.

Please try the following patch.  With it, Octave will not print
anything for fprintf ("") and it will return 0 (it should only return
-1 on a failure, so the old behavior was buggy too).

Thanks,

jwe


2002-12-17  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>

	* oct-stream.cc (printf_format_list::printf_format_list):
	Handle empty format string.


Index: src/oct-stream.cc
===================================================================
RCS file: /usr/local/cvsroot/octave/src/oct-stream.cc,v
retrieving revision 1.77
diff -c -r1.77 oct-stream.cc
*** src/oct-stream.cc	6 Nov 2002 20:38:50 -0000	1.77
--- src/oct-stream.cc	17 Dec 2002 23:26:34 -0000
***************
*** 586,645 ****
    bool have_more = true;
    bool empty_buf = true;
  
!   while (i < n)
      {
!       have_more = true;
  
!       if (! buf)
! 	{
! 	  buf = new OSSTREAM ();
! 	  empty_buf = true;
! 	}
  
!       switch (s[i])
  	{
! 	case '%':
! 	  {
! 	    if (empty_buf)
  	      {
! 		process_conversion (s, i, n, args, flags, fw, prec,
! 				    type, modifier, num_elts);
  
! 		have_more = (buf != 0);
  	      }
! 	    else
! 	      add_elt_to_list (args, flags, fw, prec, type, modifier,
! 			       num_elts);
! 	  }
! 	  break;
! 
! 	default:
! 	  {
! 	    args = 0;
! 	    flags = "";
! 	    fw = 0;
! 	    prec = 0;
! 	    modifier = '\0';
! 	    type = '\0';
! 	    *buf << s[i++];
! 	    empty_buf = false;
! 	  }
! 	  break;
! 	}
  
!       if (nconv < 0)
! 	{
! 	  have_more = false;
! 	  break;
  	}
-     }
  
!   if (have_more)
!     add_elt_to_list (args, flags, fw, prec, type, modifier, num_elts);
  
!   list.resize (num_elts);
  
!   delete buf;
  }
  
  printf_format_list::~printf_format_list (void)
--- 586,657 ----
    bool have_more = true;
    bool empty_buf = true;
  
!   if (n == 0)
      {
!       printf_format_elt *elt
! 	= new printf_format_elt ("", args, fw, prec, flags, type, modifier);
  
!       list(num_elts++) = elt;
  
!       list.resize (num_elts);
!     }
!   else
!     {
!       while (i < n)
  	{
! 	  have_more = true;
! 
! 	  if (! buf)
! 	    {
! 	      buf = new OSSTREAM ();
! 	      empty_buf = true;
! 	    }
! 
! 	  switch (s[i])
! 	    {
! 	    case '%':
  	      {
! 		if (empty_buf)
! 		  {
! 		    process_conversion (s, i, n, args, flags, fw, prec,
! 					type, modifier, num_elts);
! 
! 		    have_more = (buf != 0);
! 		  }
! 		else
! 		  add_elt_to_list (args, flags, fw, prec, type, modifier,
! 				   num_elts);
! 	      }
! 	      break;
  
! 	    default:
! 	      {
! 		args = 0;
! 		flags = "";
! 		fw = 0;
! 		prec = 0;
! 		modifier = '\0';
! 		type = '\0';
! 		*buf << s[i++];
! 		empty_buf = false;
  	      }
! 	      break;
! 	    }
  
! 	  if (nconv < 0)
! 	    {
! 	      have_more = false;
! 	      break;
! 	    }
  	}
  
!       if (have_more)
! 	add_elt_to_list (args, flags, fw, prec, type, modifier, num_elts);
  
!       list.resize (num_elts);
  
!       delete buf;
!     }
  }
  
  printf_format_list::~printf_format_list (void)



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