[patch, libfortran] Fix PR 23598, iostat handling after library error

[Thomas Koenig]

This is the reason why the original test case from
http://gcc.gnu.org/ml/fortran/2005-08/msg00307.html failed.

Regression-tested on mainline.

OK for mainline, and for 4.0 once I've regression-tested it there?

	Thomas

2005-08-28  Thomas Koenig  <Thomas.Koenig@online.de>

	PR libfortran/23598
	* io/lock.c(library_start):  If iostat is present, clear
	ioparm.library_return unconditionally.

2005-02-28  Thomas Koenig  <Thomas.Koenig@online.de>

	PR libfortran/23598
	* gfortran.dg/iostat_1.f90:  New test.

:ADDPATCH libfortran:
-------------- next part --------------
Index: lock.c
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/io/lock.c,v
retrieving revision 1.8
diff -c -p -r1.8 lock.c
*** lock.c	17 Aug 2005 02:48:56 -0000	1.8
--- lock.c	28 Aug 2005 10:53:18 -0000
*************** library_start (void)
*** 54,60 ****
       stay within the library. */
    g.in_library = 1;
  
!   if (ioparm.iostat != NULL && ioparm.library_return == LIBRARY_OK)
      *ioparm.iostat = ERROR_OK;
  
    ioparm.library_return = LIBRARY_OK;
--- 54,60 ----
       stay within the library. */
    g.in_library = 1;
  
!   if (ioparm.iostat != NULL)
      *ioparm.iostat = ERROR_OK;
  
    ioparm.library_return = LIBRARY_OK;
-------------- next part --------------
! { dg-do run }
! PR 23598 - The iostat variable wasn't reset if the previous
! I/O library call had an error.
program main
  implicit none
  integer :: ios, i
  open (10, pad='no', status='scratch')
  write (10, '(A)') '1','1'
  rewind (10)
  read (10,'(I2)',iostat=ios) i
  ios = -4321
  read (10, '(I1)', iostat=ios) i
  if (ios /= 0) call abort
end program main