From owner-bug-octave at bevo dot che dot wisc dot edu  Tue Oct 31 00:33:40 1995
Subject: Applied patch. Better, but help<CR>q crashes etc...
From: John Eaton <jwe at bevo dot che dot wisc dot edu>
To: Mirsad Todorovac <tm at rasips2 dot rasip dot etf dot hr>
Cc: bug-octave at che dot utexas dot edu
Date: Tue, 31 Oct 1995 00:31:13 -0600

Mirsad Todorovac <tm at rasips2 dot rasip dot etf dot hr> wrote:

: 	Thanks for the pointer to the patch.
: 	Now it compiled without many problems, only some suspicious warnings
: 		about something used before declared inline ... probably
: 		not important.
: 	Still, after mistyping command in command line or on breaking
: 	output of the pager it crashes unfortunatelly.

It looks like you are running into a bug in the libg++ procbuf class.
Please try the following patch.

Thanks,

jwe


>From jwe at bevo dot che dot wisc dot edu Wed Sep 20 01:48:07 CDT 1995
From: jwe at bevo dot che dot wisc dot edu (John Eaton)
Newsgroups: gnu.g++.lib.bug
Subject: procbuf problem on DEC alpha
Date: 19 Sep 1995 23:30:20 -0400
Message-ID: <199509200329 dot WAA04570 at bevo dot che dot wisc dot edu>

Using libg++ version 2.7.0 and g++ 2.7.0 on a DEC Alpha running OSF/1
3.2, I have had trouble with programs that attempted to use more than
one procbuf.  For example, the following program

#include <procbuf.h>

int
main (void)
{
  procbuf cmd ("ls -C", ios::in);
  procbuf pgr ("less", ios::out);
  char *s = "TEST";
  while (*s)
    pgr.sputc (*s++);

  return 0;
}

crashes like this:

bash$ ./foo
Unaligned access pid=8164 <foo> va=140000854 pc=12000ba04 ra=12000941c type=ldq
Unaligned access pid=8164 <foo> va=140000854 pc=12000b9f0 ra=12000941c type=ldq
Unaligned access pid=8164 <foo> va=140000854 pc=12000b9fc ra=12000941c type=ldq
Segmentation fault (core dumped)

but works if the first procbuf declaration is commented out.

The following patch seems to fix this problem:

*** procbuf.h~	Thu Jun 15 22:42:28 1995
--- procbuf.h	Tue Sep 19 21:59:18 1995
***************
*** 29,34 ****
--- 29,35 ----
  class procbuf : public filebuf {
      /* Following fields must match those in struct _IO_proc_file */
      _IO_pid_t _pid;
+     void *space_holder_for_IO_proc_file_next_field;
    public:
      procbuf() : filebuf() { }
      procbuf(const char *command, int mode);


Thanks,

jwe