JIRA REST API returned a NPE error if stated wrong transition ID

When transit an issue to another state, we refer to the following transition ID found in the GET method JSON.

For example:

1. GET http://localhost:8080/rest/api/latest/issue/TEST-1/transitions
2. The request returns the states 'Resolved' => '5', 'Closed' => '6', 'In Progress' => '3'.
3. POST http://localhost:8080/rest/api/latest/issue/TEST-1/transitions

   {"transition":{"id":"7"}}
   

4. This time with JSON data {"transition":{"id":"7"}} and get the '500 Internal Server Error' because transition ID = 7 is not exist.

   2015-01-21 17:54:29,343 http-bio-8080-exec-20 ERROR admin 1134x2089x1 xxxx xx.xx.xx.xx /rest/api/latest/issue/TEST-1/transitions [jira.rest.exception.ExceptionInterceptor] Returning internal server error in response
   java.lang.reflect.InvocationTargetException
   	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
   	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
   	at java.lang.reflect.Method.invoke(Unknown Source)
   	at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$ResponseOutInvoker$1.invoke(DispatchProviderHelper.java:234)
   	at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$1.intercept(DispatchProviderHelper.java:100)
   	at com.atlassian.plugins.rest.common.interceptor.impl.DefaultMethodInvocation.invoke(DefaultMethodInvocation.java:61)
   ...
   Caused by: java.lang.NullPointerException
   	at com.atlassian.jira.workflow.WorkflowActionsBean.getFieldScreenForView(WorkflowActionsBean.java:59)
   	at com.atlassian.jira.issue.fields.screen.StandardFieldScreenRendererFactory.getScreenFromAction(StandardFieldScreenRendererFactory.java:130)
   	at com.atlassian.jira.issue.fields.screen.StandardFieldScreenRendererFactory.createFieldScreenRenderer(StandardFieldScreenRendererFactory.java:55)
   	at com.atlassian.jira.issue.fields.screen.FieldScreenRendererFactoryImpl.getFieldScreenRenderer(FieldScreenRendererFactoryImpl.java:55)
   

The NPE error is misleading to user and it would be great if JIRA can handle the error by showing a meaningful error message. Besides being misleading it seems to indicate that there is a bug in the error handling routines, and IMHO should be fixed.