PR c++/82070 - error with nested lambda capture

	* pt.c (tsubst_expr) [DECL_EXPR]: Register capture proxies with
	register_local_specialization.

From-SVN: r251819

gcc/cp/ChangeLog

+2017-09-06  Jason Merrill  <jason@redhat.com>
+
+	PR c++/82070 - error with nested lambda capture
+	* pt.c (tsubst_expr) [DECL_EXPR]: Register capture proxies with
+	register_local_specialization.
+
 2017-09-06  Nathan Sidwell  <nathan@acm.org>
 
 	* name-lookup.h (lookup_field_1): Delete.

gcc/cp/pt.c

@@ -15985,8 +15985,11 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
 	else if (is_capture_proxy (decl)
 		 && !DECL_TEMPLATE_INSTANTIATION (current_function_decl))
 	  {
-	    /* We're in tsubst_lambda_expr, we've already inserted new capture
-	       proxies, and uses will find them with lookup_name.  */
+	    /* We're in tsubst_lambda_expr, we've already inserted a new
+	       capture proxy, so look it up and register it.  */
+	    tree inst = lookup_name (DECL_NAME (decl));
+	    gcc_assert (inst != decl && is_capture_proxy (inst));
+	    register_local_specialization (inst, decl);
 	    break;
 	  }
 	else if (DECL_IMPLICIT_TYPEDEF_P (decl)

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-nested7.C

+// PR c++/82070
+// { dg-do compile { target c++11 } }
+
+namespace a {
+template <typename b>
+void
+c (int, int, b d)
+{
+  [d] { [d] {}; };
+}
+}
+void
+e ()
+{
+  int f;
+  a::c (f, 3, [] {});
+}