re PR c++/84707 (internal compiler error: Segmentation fault (tree_check()/duplicate_decls()))

	PR c++/84707
	* decl.c (duplicate_decls): Check DECL_NAME before accessing
	UDLIT_OPER_P.

	* g++.dg/cpp0x/inline-ns10.C: New test.

From-SVN: r258255

gcc/cp/ChangeLog

+2018-03-05  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/84707
+	* decl.c (duplicate_decls): Check DECL_NAME before accessing
+	UDLIT_OPER_P.
+
 2018-03-05  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/84694

gcc/cp/decl.c

@@ -1410,7 +1410,9 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
       || TREE_TYPE (olddecl) == error_mark_node)
     return error_mark_node;
 
-  if (UDLIT_OPER_P (DECL_NAME (newdecl))
+  if (DECL_NAME (newdecl)
+      && DECL_NAME (olddecl)
+      && UDLIT_OPER_P (DECL_NAME (newdecl))
       && UDLIT_OPER_P (DECL_NAME (olddecl)))
     {
       if (TREE_CODE (newdecl) == TEMPLATE_DECL

gcc/testsuite/ChangeLog

+2018-03-05  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/84707
+	* g++.dg/cpp0x/inline-ns10.C: New test.
+
 2018-03-05  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/84694

gcc/testsuite/g++.dg/cpp0x/inline-ns10.C

+// PR c++/84707
+// { dg-do compile { target c++11 } }
+
+inline namespace {
+  namespace {}
+}
+
+namespace {} // { dg-error "conflicts" }