Description of problem:
I received Internal Server Error when I tried to add pushed package to new custom channel. ISE I receive when I click link compare packages as well.

rhn/channels/manage/ChannelPackagesAdd.do?cid=<id>

Channels -> Software Channel Management -> [choose channel] -> Packages -> Add Packages / Compare

Version-Release number of selected component (if applicable):
spacewalk-java-2.7.110-1.fc26.noarch

How reproducible:
always

Steps to Reproduce:
1. create custom parent channel
2. pushed package
3. go to detail of channel and try to add package

Actual results:
ISE

Expected results:
without ISE

Additional info:

15-Aug-2017 07:39:09.219 SEVERE [ajp-nio-0:0:0:0:0:0:0:1-8009-exec-6] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [action] in context with path [/rhn] threw exception
 javax.el.PropertyNotFoundException: Property 'parent' not found on type com.redhat.rhn.domain.channel.SelectableChannel
	at javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:269)
	at javax.el.BeanELResolver$BeanProperties.access$300(BeanELResolver.java:221)
	at javax.el.BeanELResolver.property(BeanELResolver.java:356)
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:95)
	at org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:110)
....
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
	at org.apache.coyote.ajp.AbstractAjpProcessor.process(AbstractAjpProcessor.java:877)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1533)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1489)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)