syntax = "proto3";

package test;

import "google/protobuf/descriptor.proto";

extend google.protobuf.MessageOptions {
    optional google.protobuf.MessageOptions options = 10000;
    optional int32 map_entry = 10001;
}

message Foo {
    option map_entry = true;

    // This is silly but valid and must be accepted.
    option (options).map_entry = true;
    option (map_entry) = 42;
}