Infinite loop when running a workflow with a custom element without input/output ports

#@UGENE_WORKFLOW
"java" {
    .inputs {
    }
    .outputs {
    }
    .attributes {
        -version {
            name:"-version";
            type:String;
            default-value:-version;
        }
    }
    name:"java";
    use-integrated-tool:true;
    integrated-tool-id:"java";
    cmdline:"%JAVA_HOME% $-version";