********> bugfix.29
Author:   Bill Ross
Date:     8/25/98

	  If not using Machine.g77 or Machine.f2c, ignore this fix.

Programs: most fortran programs under amber5/src/ compiled with f2c/g77

Severity: moderate

Description: Exit status is not properly returned to the command shell.
	Apparently the exit() function provided by libf2c.so has been
	modified to always return non-0 status to the shell, so an
	error is indicated when the program exits without error.

	Here is a program to check whether the fix is needed and sufficient:
----------------------------------
      program x
c     call exit(0)
      stop 1
      end
----------------------------------
	With the 'call exit' line commented as above:
	% g77 x.f
	% ./a.out || echo oops
	With the 'call exit' line enabled (by replacing 'c' with ' '):
	% g77 x.f
	% ./a.out || echo ok

	In the first case, 'oops' should not be echoed, in the second,
	'ok' should be echoed. If the opposite is observed, the bugfix
	should not be applied. Any other behavior will indicate a new
	fix is needed.


Fix:  Replace src/lib/mexit.f with the appended version and recompile
	everything under amber5/src/.
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C
C************************************************************************
C                              AMBER                                   **
C                                                                      **
C                  Copyright (c) 1986, 1991, 1995                      **
C             Regents of the University of California                  **
C                       All Rights Reserved.                           ** 
C                                                                      **
C  This software provided pursuant to a license agreement containing   **
C  restrictions on its disclosure, duplication, and use. This software **
C  contains confidential and proprietary information, and may not be   **
C  extracted or distributed, in whole or in part, for any purpose      **
C  whatsoever, without the express written permission of the authors.  **
C  This notice, and the associated author list, must be attached to    **
C  all copies, or extracts, of this software. Any additional           **
C  restrictions set forth in the license agreement also apply to this  **
C  software.                                                           **
C************************************************************************
C
C  mexit() - machine-dependent exit() procedure, designed to return an 
C            appropriate (success/failure) value to the operating system.
C
      subroutine mexit(ifil, i)
#ifdef MPI
# include "parallel.h"
# include "mpif.h"
#endif
#ifdef IBM_VM_CMS
        if (ifil.ne.0 .and. ifil.ne.6) close(unit=ifil)
#else
        if (ifil.ne.0) close(unit=ifil)
#endif
#ifdef MPI
c
c       ...i .gt. 0 implies and error condition, therefore we want to
c       kill all the nodes.  This is accomplished with mpi_abort.  If
c       it is not an error, exit gracefully with the mpi_finalize.
c       NOTE: no mpi functions may be called after a call to 
c       mpi_finalize.
c
        if (i.ne.0) then
          call MPI_ABORT(MPI_COMM_WORLD, i, ier)
        else
          call MPI_FINALIZE(ier)
        endif
#endif
#ifdef VMS
c       if anyone knows how to get a reasonable %DCL msg w/ exit
c       status, please send it in. this will at least cause DCL
c       "on error then goto BOMB" to trap.
c
        if (i.ne.0) then
c         exit with an _even_ value to signal error
          call exit(2)
        else
          call exit(1)
        endif
        
#else 
#ifdef F2C
        if (i.ne.0) then
          call exit(1)
        else
          stop 0
        endif
#else
#if rs6000 || IBM3090
        if (i.ne.0) then
          stop 1
        else
          stop 0
        endif
#else
#ifdef HP
        if (i.ne.0) then
          call exit(1)
        else
          stop 'ok'
        endif
#else
#ifdef UXP
        call setrcd(i)
#else
        call exit(i)
#endif
#endif
#endif
#endif
#endif
      end
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