re PR c++/51530 ([C++0x] internal compiler error: in unify, at cp/pt.c:16854)

	PR c++/51530
	* pt.c (unify): Handle NULLPTR_TYPE.

From-SVN: r182505

gcc/cp/ChangeLog

 2011-12-19  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51530
+	* pt.c (unify): Handle NULLPTR_TYPE.
+
 	PR c++/51526
 	* semantics.c (build_data_member_initialization): Handle
 	delegating constructor.

gcc/cp/pt.c

@@ -16614,6 +16614,7 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
     case BOOLEAN_TYPE:
     case ENUMERAL_TYPE:
     case VOID_TYPE:
+    case NULLPTR_TYPE:
       if (TREE_CODE (arg) != TREE_CODE (parm))
 	return unify_type_mismatch (explain_p, parm, arg);
 

gcc/testsuite/ChangeLog

+2011-12-19  Jason Merrill  <jason@redhat.com>
+
+	PR c++/51530
+	* g++.dg/cpp0x/nullptr26.C: New.
+
 2011-12-19  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* gcc.target/mips/mult-1.c: Require -O2.

gcc/testsuite/g++.dg/cpp0x/nullptr26.C

+// PR c++/51530
+// { dg-options -std=c++0x }
+
+template <class T, class U>
+void f(T, U);
+
+template <class T>
+void f(T, decltype(nullptr));
+
+int main()
+{
+  f(1, nullptr);
+}