Re: [Bug libfortran/26423][4.1/4.2 Regression] Error on binary I/O for large array

[Jerry DeLisle <jvdelisle at verizon dot net>]

The attached patch fixes this regression.  It is a revert of changes made to 
unix.c in patch for PR25949.  Bootstrapped, regtested, NIST tested, tested with 
the test case attached.

OK for 4.2?

Mark can you get this into 4.1 before release?

Regards,

Jerry

2006-02-24  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR libgfortran/26423
	* io/unix.c (fd_seek): Revert change from 25949.
	(fd_read): Same.
	(fd_write): Same.

Index: io/unix.c
===================================================================
*** io/unix.c	(revision 111412)
--- io/unix.c	(working copy)
*************** fd_sfree (unix_stream * s)
*** 562,570 ****
  static try
  fd_seek (unix_stream * s, gfc_offset offset)
  {
!   s->logical_offset = offset;
  
!   return SUCCESS;
  }
  
  
--- 562,576 ----
  static try
  fd_seek (unix_stream * s, gfc_offset offset)
  {
!   if (s->physical_offset == offset) /* Are we lucky and avoid syscall?  */
!     {
!       s->logical_offset = offset;
!       return SUCCESS;
!     }
  
!   s->physical_offset = s->logical_offset = offset;
! 
!   return (lseek (s->fd, offset, SEEK_SET) < 0) ? FAILURE : SUCCESS;
  }
  
  
*************** fd_read (unix_stream * s, void * buf, si
*** 666,673 ****
        return errno;
      }
  
!   if (is_seekable ((stream *) s) && s->physical_offset != s->logical_offset 
!       && lseek (s->fd, s->logical_offset, SEEK_SET) < 0)
      {
        *nbytes = 0;
        return errno;
--- 672,678 ----
        return errno;
      }
  
!   if (is_seekable ((stream *) s) && fd_seek (s, s->logical_offset) == FAILURE)
      {
        *nbytes = 0;
        return errno;
*************** fd_write (unix_stream * s, const void * 
*** 715,722 ****
        return errno;
      }
  
!   if (is_seekable ((stream *) s) && s->physical_offset != s->logical_offset
!       && lseek (s->fd, s->logical_offset, SEEK_SET) < 0)
      {
        *nbytes = 0;
        return errno;
--- 720,726 ----
        return errno;
      }
  
!   if (is_seekable ((stream *) s) && fd_seek (s, s->logical_offset) == FAILURE)
      {
        *nbytes = 0;
        return errno;

!{ dg-do run }
! PR26423 Large file I/O error related to buffering
! Test case derived from case by Dale Ranta.
! Submitted  by Jerry DeLisle  <jvdelisle@gcc.gnu.org> 
      integer :: a(3000) , b(2048)
      a=3
      b=5
      a(1) = 1
      a(3000)=1234
      write(2) a
      b(1) = 2
      b(2048) = 5678
      write(2) b
      rewind 2
      read(2) a
      read(2) b
      if (a(1).ne.1) call abort()
      if (a(2).ne.3) call abort()
      if (b(1).ne.2) call abort()
      if (b(2).ne.5) call abort()
      if (a(3000).ne.1234) call abort()
      if (b(2048).ne.5678) call abort()
      end