From 71b3723abb23b848ed7a647506345cdfaa03fddb Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Sat, 23 Jul 2016 22:50:16 -0400
Subject: [PATCH] PR c++/70778 - member template template parameter

	* pt.c (tsubst): Also substitute into the template of a
	BOUND_TEMPLATE_TEMPLATE_PARM.

From-SVN: r238686
---
 gcc/cp/ChangeLog                      |  4 ++++
 gcc/cp/pt.c                           | 11 +++++++++--
 gcc/testsuite/g++.dg/template/ttp29.C | 21 +++++++++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/template/ttp29.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c9a28aed253..e5275f51020 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2016-07-23  Jason Merrill  <jason@redhat.com>
 
+	PR c++/70778
+	* pt.c (tsubst): Also substitute into the template of a
+	BOUND_TEMPLATE_TEMPLATE_PARM.
+
 	PR c++/71738
 	* pt.c (lookup_template_class_1): Handle getting template from tsubst.
 
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index a44beadd8af..65fa9825862 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -13232,13 +13232,20 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 
 		if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
 		  {
-		    tree argvec = tsubst (TYPE_TI_ARGS (t), args,
+		    tree tinfo = TYPE_TEMPLATE_INFO (t);
+		    /* We might need to substitute into the types of non-type
+		       template parameters.  */
+		    tree tmpl = tsubst (TI_TEMPLATE (tinfo), args,
+					complain, in_decl);
+		    if (tmpl == error_mark_node)
+		      return error_mark_node;
+		    tree argvec = tsubst (TI_ARGS (tinfo), args,
 					  complain, in_decl);
 		    if (argvec == error_mark_node)
 		      return error_mark_node;
 
 		    TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
-		      = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
+		      = build_template_info (tmpl, argvec);
 		  }
 	      }
 	    break;
diff --git a/gcc/testsuite/g++.dg/template/ttp29.C b/gcc/testsuite/g++.dg/template/ttp29.C
new file mode 100644
index 00000000000..7d4e03ab20b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/ttp29.C
@@ -0,0 +1,21 @@
+// PR c++/70778
+
+template <class KeyType>
+struct Stuff
+{
+  template <KeyType, class>
+  struct AddToFront;
+
+  template <KeyType ToAdd, template<KeyType> class Holder, KeyType Indexs>
+  struct AddToFront<ToAdd, Holder<Indexs> >
+  {
+  };
+};
+
+template <unsigned>
+struct Holder {};
+
+int main()
+{
+  Stuff<unsigned>::AddToFront<0, Holder<24> > t;
+}
-- 
2.30.2