Editing a comment loses formatting

After editing a comment, any formatting that had been in the comment is lost.

Example before edit:

            with self.rt.instance_claim(context, instance, node, allocations,
                                        limits):
                self.network_api.setup_instance_network_on_host(
                    context, instance, self.host,
                    provider_mappings=provider_mappings)
                network_info = self.network_api.get_instance_nw_info(
                    context, instance)

Example after edit:

with self.rt.instance_claim(context, instance, node, allocations,
limits):
self.network_api.setup_instance_network_on_host(
context, instance, self.host,
provider_mappings=provider_mappings)
network_info = self.network_api.get_instance_nw_info(
context, instance)