re PR c++/27425 (ICE with invalid template-template-parameter)

	PR c++/27425
	PR c++/34274
	* pt.c (expand_template_argument_pack): Handle null arg gracefully.
	(convert_template_argument): Use %T for type.

From-SVN: r154164

gcc/cp/ChangeLog

 2009-11-13  Jason Merrill  <jason@redhat.com>
 
+	PR c++/27425
+	PR c++/34274
+	* pt.c (expand_template_argument_pack): Handle null arg gracefully.
+	(convert_template_argument): Use %T for type.
+
 	PR c++/29363
 	* decl.c (create_implicit_typedef): Set TYPE_STUB_DECL here.
 	(cxx_init_decl_processing): Not here.

gcc/cp/pt.c

@@ -3150,6 +3150,8 @@ expand_template_argument_pack (tree args)
   for (in_arg = 0; in_arg < nargs; ++in_arg)
     {
       tree arg = TREE_VEC_ELT (args, in_arg);
+      if (arg == NULL_TREE)
+	return args;
       if (ARGUMENT_PACK_P (arg))
         {
           int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
@@ -5472,7 +5474,7 @@ convert_template_argument (tree parm,
 		      error ("type/value mismatch at argument %d in "
 			     "template parameter list for %qD",
 			     i + 1, in_decl);
-		      error ("  expected a template of type %qD, got %qD",
+		      error ("  expected a template of type %qD, got %qT",
 			     parm, orig_arg);
 		    }
 

gcc/testsuite/ChangeLog

 2009-11-13  Jason Merrill  <jason@redhat.com>
 
+	PR c++/27425
+	PR c++/34274
+	* g++.dg/template/arg7.C: New.
+
 	PR c++/29363
 	* g++.dg/template/error43.C: New.
 

gcc/testsuite/g++.dg/template/arg7.C

+// PR c++/27425, 34274
+
+template<typename T> struct A
+{
+  template<template<T> class> struct B {}; // { dg-error "void|mismatch|expected" }
+  // { dg-bogus "not supported" "" { target *-*-* } 5 }
+  template<T> struct C;			   // { dg-error "void" }
+  B<C> b;
+};
+
+A<void> a;			// { dg-message "instantiated" }