Restart job execution can have its own job parameters, but it should also take the job parameters from the previous job execution as default values, i.e., if a property value is not found in current job parameters, the value in previous job parameters (if present) should be used.

See RI bug 5779 DeciderTests#testDeciderTransitionFromSplitAndAllowRestart incorrectly sets restart parameters
https://java.net/bugzilla/show_bug.cgi?id=5779

RI Bug 4562 JobParameters on restart
https://java.net/bugzilla/show_bug.cgi?id=4562