The GCStoGCS operator using the _replace=False_ flag and specifying _source_object != destination_object_, will not work properly, because it is comparing [apples](https://github.com/apache/airflow/blob/main/airflow/providers/google/cloud/transfers/gcs_to_gcs.py#L351) with [pears](https://github.com/apache/airflow/blob/0dd70de9492444d52e0afaadd7a510fc8a95369c/airflow/providers/google/cloud/transfers/gcs_to_gcs.py#L357).

Cause: the _prefix_ in the _pears_ case needs to be calculated from the _destination_object_, however, it is coming from the _source_object_.




airflow/providers/google/cloud/transfers/gcs_to_gcs.py
hook = GCSHook(
            gcp_conn_id=self.gcp_conn_id,
            delegate_to=self.delegate_to,
            impersonation_chain=self.impersonation_chain,
        )
        if self.source_objects and self.source_object:
            error_msg = (
                "You can either set source_object parameter or source_objects "
                "parameter but not both. Found source_object={} and"
                " source_objects={}".format(self.source_object, self.source_objects)
            )
            raise AirflowException(error_msg)
        if not self.source_object and not self.source_objects:
            error_msg = "You must set source_object parameter or source_objects parameter. None set"
            raise AirflowException(error_msg)
        if self.source_objects and not all(isinstance(item, str) for item in self.source_objects):
            raise AirflowException('At least, one of the `objects` in the `source_objects` is not a string')
        
        if self.source_object:
            self.source_objects = [self.source_object]
        if self.destination_bucket is None:
            self.log.warning(
                'destination_bucket is None. Defaulting it to source_bucket (%s)', self.source_bucket
            )
            self.destination_bucket = self.source_bucket
        
        if len(self.source_objects) == 0:
            self.source_objects = ['']