1 files changed, 31 insertions, 17 deletions

diff --git a/gcc/ada/a-cdlili.adb b/gcc/ada/a-cdlili.adb
index f56578c0364..55defaec254 100644
--- a/gcc/ada/a-cdlili.adb
+++ b/gcc/ada/a-cdlili.adb
@@ -219,6 +219,29 @@ package body Ada.Containers.Doubly_Linked_Lists is
       pragma Warnings (On);
    end Clear;
 
+   ------------------------
+   -- Constant_Reference --
+   ------------------------
+
+   function Constant_Reference
+     (Container : aliased List;
+      Position  : Cursor) return Constant_Reference_Type
+   is
+   begin
+      if Position.Container = null then
+         raise Constraint_Error with "Position cursor has no element";
+      end if;
+
+      if Position.Container /= Container'Unrestricted_Access then
+         raise Program_Error with
+           "Position cursor designates wrong container";
+      end if;
+
+      pragma Assert (Vet (Position), "bad cursor in Constant_Reference");
+
+      return (Element => Position.Node.Element'Access);
+   end Constant_Reference;
+
    --------------
    -- Contains --
    --------------
@@ -1277,31 +1300,22 @@ package body Ada.Containers.Doubly_Linked_Lists is
    -- Reference --
    ---------------
 
-   function Constant_Reference
-     (Container : List;
-      Position  : Cursor) return Constant_Reference_Type
-   is
-   begin
-      pragma Unreferenced (Container);
-
-      if Position.Container = null then
-         raise Constraint_Error with "Position cursor has no element";
-      end if;
-
-      return (Element => Position.Node.Element'Access);
-   end Constant_Reference;
-
    function Reference
-     (Container : List;
+     (Container : aliased in out List;
       Position  : Cursor) return Reference_Type
    is
    begin
-      pragma Unreferenced (Container);
-
       if Position.Container = null then
          raise Constraint_Error with "Position cursor has no element";
       end if;
 
+      if Position.Container /= Container'Unchecked_Access then
+         raise Program_Error with
+           "Position cursor designates wrong container";
+      end if;
+
+      pragma Assert (Vet (Position), "bad cursor in function Reference");
+
       return (Element => Position.Node.Element'Access);
    end Reference;