Subdoc: Race in checking for already-existing Deleted document with Add|CreateAsDeleted

  @RepeatedTest(5000)

  void insertConflictDetected() throws InterruptedException {

    String id = UUID.randomUUID().toString();

    AtomicInteger errorCount = new AtomicInteger();

    Runnable r = () -> {

      try {

        collection.mutateIn(id, Arrays.asList(

                        MutateInSpec.upsert("txn", JsonObject.create()).xattr().createPath(),

                MutateInSpec.upsert("txn.op.crc32", MutateInMacro.VALUE_CRC_32C).xattr()),

                mutateInOptions()

                        // If next line is removed, test passes

                        .durability(DurabilityLevel.MAJORITY)

                        .storeSemantics(StoreSemantics.INSERT)

                        .accessDeleted(true)

                        .createAsDeleted(true)

        );

      } catch (DocumentExistsException err) {

        errorCount.incrementAndGet();

      }

      catch (RuntimeException err) {

        fail();

      }

    };

    Thread t1 = new Thread(r);

    Thread t2 = new Thread(r);

    t1.start();

    t2.start();

    t1.join();

    t2.join();

    // Intermittently this fails as errorCount is 0 - both operations have succeeded

    assertEquals(1, errorCount.get());

  }