re PR fortran/35724 (Compile time segmentation fault for CSHIFT with negative third arg)

2008-03-27  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/35724
	* iresolve.c (gfc_resolve_cshift): Check for NULL symtree in test for
	optional argument attribute.

From-SVN: r133668

gcc/fortran/ChangeLog

+2008-03-27  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+	PR fortran/35724
+	* iresolve.c (gfc_resolve_cshift): Check for NULL symtree in test for
+	optional argument attribute.
+
 2008-03-27  Tom Tromey  <tromey@redhat.com>
 
 	* Make-lang.in: Revert automatic dependency patch.

gcc/fortran/iresolve.c

@@ -597,7 +597,8 @@ gfc_resolve_cshift (gfc_expr *f, gfc_expr *array, gfc_expr *shift,
  
   if (dim != NULL)
     {
-      if (dim->expr_type != EXPR_CONSTANT && dim->symtree->n.sym->attr.optional)
+      if (dim->expr_type != EXPR_CONSTANT && dim->symtree != NULL
+	  && dim->symtree->n.sym->attr.optional)
 	{
 	  /* Mark this for later setting the type in gfc_conv_missing_dummy.  */
 	  dim->representation.length = shift->ts.kind;