symbol.c (gfc_undo_symbols): Correctly undo namelists.

fortran/
	* symbol.c (gfc_undo_symbols): Correctly undo namelists.

testsuite/
	* gfortran.dg/namelist_75.f90: New test.

From-SVN: r191357

gcc/fortran/ChangeLog

+2012-09-16  Mikael Morin  <mikael@gcc.gnu.org>
+
+	* symbol.c (gfc_undo_symbols): Correctly undo namelists.
+
 2012-09-15  Tobias Burnus  <burnus@net-b.de>
 
 	* trans-io.c (gfc_trans_transfer): Add an assert.

gcc/fortran/symbol.c

@@ -2996,7 +2996,7 @@ gfc_undo_symbols (void)
 	{
 	  if (p->namelist_tail != old->namelist_tail)
 	    {
-	      gfc_free_namelist (old->namelist_tail);
+	      gfc_free_namelist (old->namelist_tail->next);
 	      old->namelist_tail->next = NULL;
 	    }
 	}

gcc/testsuite/ChangeLog

+2012-09-16  Mikael Morin  <mikael@gcc.gnu.org>
+
+	* gfortran.dg/namelist_75.f90: New test.
+
 2012-09-15  Tom de Vries  <tom@codesourcery.com>
 
 	* gcc.dg/tree-ssa/vrp82.c: New test.

gcc/testsuite/gfortran.dg/namelist_75.f90

+! { dg-do compile }
+!
+! Tests a write-after-free memory error fix in gfc_undo_symbols
+
+program test_nml
+
+  namelist /foo/ bar, baz
+  namelist /foo/ wrong, ,  ! { dg-error "Syntax error in NAMELIST" }
+
+end program test_nml