From d808e92ea950feeba41a5019ada7cddbbe0a5ed7 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 25 Feb 2014 13:53:45 -0500
Subject: [PATCH] DR 1286 PR c++/60328

	DR 1286
	PR c++/60328
	* pt.c (get_underlying_template): Fix equivalence calculation.

From-SVN: r208152
---
 gcc/cp/ChangeLog                                |  6 ++++++
 gcc/cp/pt.c                                     |  7 +++++--
 gcc/testsuite/g++.dg/cpp0x/alias-decl-dr1286b.C | 12 ++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/alias-decl-dr1286b.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 5afc6d8..7f63b8e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2014-02-25  Jason Merrill  <jason@redhat.com>
+
+	DR 1286
+	PR c++/60328
+	* pt.c (get_underlying_template): Fix equivalence calculation.
+
 2014-02-25  Adam Butcher  <adam@jessamine.co.uk>
 
 	PR c++/60311
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index bd59142..4a9fa71 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -5185,9 +5185,12 @@ get_underlying_template (tree tmpl)
 	  tree sub = TYPE_TI_TEMPLATE (result);
 	  if (PRIMARY_TEMPLATE_P (sub)
 	      && (num_innermost_template_parms (tmpl)
-		  == num_innermost_template_parms (sub))
-	      && same_type_p (result, TREE_TYPE (sub)))
+		  == num_innermost_template_parms (sub)))
 	    {
+	      tree alias_args = INNERMOST_TEMPLATE_ARGS
+		(template_parms_to_args (DECL_TEMPLATE_PARMS (tmpl)));
+	      if (!comp_template_args (TYPE_TI_ARGS (result), alias_args))
+		break;
 	      /* The alias type is equivalent to the pattern of the
 		 underlying template, so strip the alias.  */
 	      tmpl = sub;
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-dr1286b.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-dr1286b.C
new file mode 100644
index 0000000..fef9818
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-dr1286b.C
@@ -0,0 +1,12 @@
+// PR c++/60328
+// { dg-require-effective-target c++11 }
+
+template <class _T, class... _Rest>
+struct Foo
+{
+  template <class _TT, class... _RR>
+  using Bar = Foo<_TT, _RR...>;
+
+  using Normal = Foo<_Rest...>;
+  using Fail = Bar<_Rest...>;
+};
-- 
2.7.4