Description of problem:
This issue is similar like JBEAP-6043. Tab completion throws IllegalArgumentException after two '{' characters and '=' character. Or tab completition returns unlimited count of ')' characters.

How reproducible:
Always

1. Steps to Reproduce:

Get fresh EAP.
./standalone.sh &
./jboss-cli.sh -c
/subsystem=elytron/simple-permission-mapper=login-permission-mapper2:add(permission-mappings=[{roles=[{role<TAB><TAB><TAB><TAB><TAB><TAB><TAB><TAB><TAB><TAB>

1. Actual results:

/subsystem=elytron/simple-permission-mapper=login-permission-mapper2:add(permission-mappings=[{roles=[{role))))))))))

2. Steps to Reproduce:

./standalone.sh -c standalone-elytron.xml &
./jboss-cli.sh -c
/subsystem=elytron/simple-permission-mapper=login-permission-mapper2:add(permission-mappings=[{roles=[{role=<TAB>

2. Actual results:

• java.lang.IllegalArgumentException
• Details:

  [mkopecky@dhcp-10-40-5-171 bin]$ ./jboss-cli.sh -c
  [standalone@localhost:9990 /] /subsystem=elytron/simple-permission-mapper=login-permission-mapper2:add(permission-mappings=[{roles=[{role=Exception in thread "Aesh Process Loop 30318020" java.lang.IllegalArgumentException
  	at org.jboss.dmr.ModelValue.getChild(ModelValue.java:115)
  	at org.jboss.dmr.ModelNode.get(ModelNode.java:861)
  	at org.jboss.as.cli.impl.ValueTypeCompleter$ValueTypeCallbackHandler.getCandidates(ValueTypeCompleter.java:475)
  	at org.jboss.as.cli.impl.ValueTypeCompleter.complete(ValueTypeCompleter.java:321)
  	at org.jboss.as.cli.operation.OperationRequestCompleter.complete(OperationRequestCompleter.java:254)
  	at org.jboss.as.cli.operation.OperationRequestCompleter.complete(OperationRequestCompleter.java:74)
  	at org.jboss.as.cli.CommandCompleter.doComplete(CommandCompleter.java:137)
  	at org.jboss.as.cli.CommandCompleter.complete(CommandCompleter.java:64)
  	at org.jboss.as.cli.impl.Console$Factory$1$1.complete(Console.java:143)
  	at org.jboss.aesh.console.AeshCompletionHandler.complete(AeshCompletionHandler.java:155)
  	at org.jboss.aesh.console.AeshInputProcessor.complete(AeshInputProcessor.java:427)
  	at org.jboss.aesh.console.AeshInputProcessor.parseOperation(AeshInputProcessor.java:165)
  	at org.jboss.aesh.console.Console.processInternalOperation(Console.java:773)
  	at org.jboss.aesh.console.Console.execute(Console.java:733)
  	at org.jboss.aesh.console.Console.access$900(Console.java:73)
  	at org.jboss.aesh.console.Console$6.run(Console.java:642)
  	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  	at java.lang.Thread.run(Thread.java:745)
  [mkopecky@dhcp-10-40-5-171 bin]$