re PR c++/18100 (template member with same name as class not rejected)

	PR c++/18100
	* decl.c (lookup_and_check_tag): Diagnose nested class with
	the same name as enclosing class.

	* g++.dg/lookup/name-clash4.C: New test.

From-SVN: r91866

gcc/cp/ChangeLog

+2004-12-08  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>
+
+	PR c++/18100
+	* decl.c (lookup_and_check_tag): Diagnose nested class with 
+	the same name as enclosing class.
+
 2004-12-08  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/18803

gcc/cp/decl.c

@@ -9169,6 +9169,18 @@ lookup_and_check_tag (enum tag_types tag_code, tree name,
 
   if (decl && TREE_CODE (decl) == TYPE_DECL)
     {
+      /* Look for invalid nested type:
+	   class C {
+	     class C {};
+	   };  */
+      if (scope == ts_current && DECL_SELF_REFERENCE_P (decl))
+	{
+	  error ("%qD has the same name as the class in which it is "
+		 "declared",
+		 decl);
+	  return error_mark_node;
+	}
+
       /* Two cases we need to consider when deciding if a class
 	 template is allowed as an elaborated type specifier:
 	 1. It is a self reference to its own class.

gcc/testsuite/ChangeLog

+2004-12-08  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>
+
+	PR c++/18100
+	* g++.dg/lookup/name-clash4.C: New test.
+
 2004-12-08  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/18672

gcc/testsuite/g++.dg/lookup/name-clash4.C

+// { dg-do compile }
+
+// Origin: Volker Reichelt <reichelt@gcc.gnu.org>
+
+// PR c++/18100: Invalid nested type.
+
+struct A
+{
+    template<int> struct A {};	// { dg-error "same name" }
+};
+
+A::A<0> a;			// { dg-error "not a template" }