[patch, committed] PR92100 Formatted stream IO irreproducible read with binary data in file

[Jerry DeLisle]

Committed this as simple one liner.  I will probably backport this in a few 
days.
Jerry

Committed r278660
        M       libgfortran/ChangeLog
        M       libgfortran/io/transfer.c

2019-11-24  Jerry DeLisle  <jvdeli...@gcc.ngu.org>

        PR fortran/92100
        io/transfer.c (data_transfer_init_worker): Use fbuf_reset
        instead of fbuf_flush before the seek. Note that fbuf_reset
        calls fbuf_flush and adjusts fbuf pointers.

diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 6382d0dad09..bb104db3584 100644
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -3273,8 +3273,9 @@ data_transfer_init_worker (st_parameter_dt *dtp, int 
read_flag)

           if (dtp->pos != dtp->u.p.current_unit->strm_pos)
             {
-              fbuf_flush (dtp->u.p.current_unit, dtp->u.p.mode);
-              if (sseek (dtp->u.p.current_unit->s, dtp->pos - 1, SEEK_SET) < 0)
+             fbuf_reset (dtp->u.p.current_unit);
+             if (sseek (dtp->u.p.current_unit->s, dtp->pos - 1,
+                        SEEK_SET) < 0)
                 {
                   generate_error (&dtp->common, LIBERROR_OS, NULL);
                   return;