[Patch, libgfortran] PR68987 [5/6 Regression] double free or corruption in _gfortran_st_write_done

[Jerry DeLisle]

Attached patch eliminate this problem by reverting a portion of the previous
patch to pr65089.

Regression tested on x86_64-Linux.  I will add test case from the PR.

OK for trunk and then back port to 5x?

Regards,

Jerry

2015-12-26  Jerry DeLisle  <jvdeli...@gcc.gnu.org>

        PR libfortran/68987
        io/format.c (format_error): Remove unneeded memory cleanup.

diff --git a/libgfortran/io/format.c b/libgfortran/io/format.c
index 2068af7e..fc7785e1 100644
--- a/libgfortran/io/format.c
+++ b/libgfortran/io/format.c
@@ -1180,26 +1180,6 @@ format_error (st_parameter_dt *dtp, const fnode *f, const char *message)
   *p++ = '^';
   *p = '\0';
 
-  /* Cleanup any left over memory allocations before calling generate
-     error.  */
-  if (is_internal_unit (dtp))
-    {
-      if (dtp->format != NULL)
-	{
-	  free (dtp->format);
-	  dtp->format = NULL;
-	}
-
-      /* Leave these alone if IOSTAT was given because execution will
-	 return from generate error in those cases.  */
-      if (!(dtp->common.flags & IOPARM_HAS_IOSTAT))
-	{
-	  free (dtp->u.p.fmt);
-	  free_format_hash_table (dtp->u.p.current_unit);
-	  free_internal_unit (dtp);
-	}
-    }
-
   generate_error (&dtp->common, LIBERROR_FORMAT, buffer);
 }