[patch, libgfortran] PR77707 formatted direct access: nextrec off by one

[Jerry DeLisle]

I plan to commit the attached patch in the next few days. Fairly simple.

Regression tested on x86-64.

Regards,

Jerry

2016-09-27  Jerry DeLisle  <jvdeli...@gcc.gnu.org>

        PR libgfortran/77707
        io/transfer.c (next_record): Flush before calculating next_record.
        Correctly calculate.

diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 6009c123..902c0201 100644
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -3720,6 +3720,8 @@ next_record (st_parameter_dt *dtp, int done)
   else
     next_record_w (dtp, done);
 
+  fbuf_flush (dtp->u.p.current_unit, dtp->u.p.mode);
+
   if (!is_stream_io (dtp))
     {
       /* Since we have changed the position, set it to unspecified so
@@ -3733,8 +3735,8 @@ next_record (st_parameter_dt *dtp, int done)
 	  fp = stell (dtp->u.p.current_unit->s);
 	  /* Calculate next record, rounding up partial records.  */
 	  dtp->u.p.current_unit->last_record =
-	    (fp + dtp->u.p.current_unit->recl - 1) /
-	      dtp->u.p.current_unit->recl;
+	    (fp + dtp->u.p.current_unit->recl) /
+	      dtp->u.p.current_unit->recl - 1;
 	}
       else
 	dtp->u.p.current_unit->last_record++;
@@ -3743,7 +3745,6 @@ next_record (st_parameter_dt *dtp, int done)
   if (!done)
     pre_position (dtp);
 
-  fbuf_flush (dtp->u.p.current_unit, dtp->u.p.mode);
   smarkeor (dtp->u.p.current_unit->s);
 }
 

! { dg-do run }
! PR77707 formatted direct access: nextrec off by one
program directaccess_formatted
  integer nextrec
  open(10, status='scratch', form='formatted', access='direct', recl=10*4)
  write(10,'(10i4)',rec=9) 1,2,3,4,5,6,7,8,9,10
  inquire(unit=10,nextrec=nextrec)
  if (nextrec.ne.10) call abort
  close(10)
end