re PR libfortran/45723 (opening /dev/null for appending writes)

2010-09-21  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR libfortran/45723
	* io/open.c (new_unit): On POSITION_APPEND don't seek if file length is
	zero.

From-SVN: r164507

libgfortran/ChangeLog

+2010-09-21  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR libfortran/45723
+	* io/open.c (new_unit): On POSITION_APPEND don't seek if file length is
+	zero.
+
 2010-09-14  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libfortran/45532
@@ -6,7 +12,8 @@
 
 2010-09-12  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 
-	* intrinsics/pack_generic.c (pack): Add missing return and fix whitespace.
+	* intrinsics/pack_generic.c (pack): Add missing return and fix
+	whitespace.
 	* intrinsics/cshift0.c (cshift0): Fix whitespace.
 	* intrinsics/unpack_generic.c (unpack1, unpack0): Fix whitespace.
 

libgfortran/io/open.c

@@ -555,7 +555,7 @@ new_unit (st_parameter_open *opp, gfc_unit *u, unit_flags * flags)
 
   if (flags->position == POSITION_APPEND)
     {
-      if (sseek (u->s, 0, SEEK_END) < 0)
+      if (file_size (opp->file, opp->file_len) > 0 && sseek (u->s, 0, SEEK_END) < 0)
 	generate_error (&opp->common, LIBERROR_OS, NULL);
       u->endfile = AT_ENDFILE;
     }