src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/abi/ProgrammableUpcallHandler.java

@@ -113,11 +113,11 @@
              if (mh.type().returnType() != void.class) {
                  BindingInterpreter.unbox(o, callingSequence.returnBindings(),
                          (storage, type, value) -> {
                              MemoryAddress ptr = bufferBase.addOffset(layout.retOffset(storage));
                              SharedUtils.writeOverSized(ptr, type, value);
-                         }, new ArrayList<>());
+                         }, null);
              }
  
              if (DEBUG) {
                  System.err.println("Buffer state after:");
                  layout.dump(abi.arch, buffer, System.err);