re PR c++/19498 (ICE on invalid reference in template parameter)

	PR c++/19498
	* pt.c (tsubst_decl) <case TEMPLATE_DECL>: Return ERROR_MARK_NODE
	if substitution of template args did not succeed.

	* g++.dg/template/instantiate7.C: New test.

From-SVN: r102818

gcc/cp/ChangeLog

+2005-08-06  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
+
+	PR c++/19498
+	* pt.c (tsubst_decl) <case TEMPLATE_DECL>: Return ERROR_MARK_NODE
+	if substitution of template args did not succeed.
+
 2005-08-06  Michael Matz  <matz@suse.de>
 
 	* method.c (use_thunk): Call init_insn_lengths.

gcc/cp/pt.c

@@ -6224,6 +6224,8 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
 	  : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
 	full_args = tsubst_template_args (tmpl_args, args,
 					  complain, in_decl);
+	if (full_args == error_mark_node)
+	  return error_mark_node;
 
 	/* tsubst_template_args doesn't copy the vector if
 	   nothing changed.  But, *something* should have

gcc/testsuite/ChangeLog

+2005-08-06  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
+
+	PR c++/19498
+	* g++.dg/template/instantiate7.C: New test.
+
 2005-08-06  Joseph S. Myers  <joseph@codesourcery.com>
 
 	PR c/23113

gcc/testsuite/g++.dg/template/instantiate7.C

+// PR c++/19498
+// Origin: Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
+// { dg-do compile }
+
+template<typename T> struct A
+{
+    template<T&> struct B;  // { dg-error "reference to void" }
+};
+
+A<void> a;                  // { dg-error "instantiated" }