Vaadin has the worst bug tracker

I tried to report a bug in vaadin bug tracker and I am fed up.

I will post the bug here. If you guys are intrested look else just ****
Vaadin doesn't has the professionalism of an open source product.

Component : Combobox,  Container : IndexedContainer
Null selection allowed

Steps :
1. populate combobox
2. select an item in combobox
3. call   ComboBox.clear()  or Combobox.select( ComboBox.getNullSelectionItemId() )   from any other Components(say another combobox) event
Throws nullpointer Exception
While calling clear combobox, combobox was disabled

Stacktrace :
com.vaadin.event.ListenerMethod$MethodException: Invocation of method valueChange in com.company.webApp.ui.viewImpl.SearchViewImpl$5 failed.
    at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:528)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:198)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)
    at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:977)
    at com.vaadin.ui.AbstractField.fireValueChange(AbstractField.java:1137)
    at com.vaadin.ui.AbstractField.setValue(AbstractField.java:548)
    at com.vaadin.ui.AbstractSelect.setValue(AbstractSelect.java:709)
    at com.vaadin.ui.AbstractSelect.setValue(AbstractSelect.java:678)
    at com.vaadin.ui.AbstractField.clear(AbstractField.java:1518)
    at com.company.webApp.ui.viewImpl.SearchViewImpl$6.focus(SearchViewImpl.java:252)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:198)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)
    at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:977)
    at com.vaadin.ui.ComboBox.changeVariables(ComboBox.java:700)
    at com.vaadin.server.communication.ServerRpcHandler.changeVariables(ServerRpcHandler.java:486)
    at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:305)
    at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:184)
    at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:92)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1408)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:350)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.vaadin.spring.http.HttpResponseFilter.doFilter(HttpResponseFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:186)
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:113)
    at org.springframework.boot.context.web.ErrorPageFilter.access$000(ErrorPageFilter.java:59)
    at org.springframework.boot.context.web.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:106)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:71)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:724)
Caused by: com.vaadin.event.ListenerMethod$MethodException: Invocation of method valueChange in com.company.webApp.ui.viewImpl.SearchViewImpl$4 failed.
    at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:528)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:198)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)
    at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:977)
    at com.vaadin.ui.AbstractField.fireValueChange(AbstractField.java:1137)
    at com.vaadin.ui.AbstractField.setValue(AbstractField.java:548)
    at com.vaadin.ui.AbstractSelect.setValue(AbstractSelect.java:709)
    at com.vaadin.ui.AbstractSelect.setValue(AbstractSelect.java:678)
    at com.vaadin.ui.AbstractField.clear(AbstractField.java:1518)
    at com.company.webApp.ui.viewImpl.SearchViewImpl$5.valueChange(SearchViewImpl.java:228)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508)
    ... 76 more
Caused by: java.lang.NullPointerException
    at org.vaadin.spring.events.internal.AbstractListenerWrapper.supports(AbstractListenerWrapper.java:61)
    at org.vaadin.spring.events.internal.MethodListenerWrapper.supports(MethodListenerWrapper.java:96)
    at org.vaadin.spring.events.internal.ListenerCollection.addSupportedListenersToSet(ListenerCollection.java:144)
    at org.vaadin.spring.events.internal.ListenerCollection.publish(ListenerCollection.java:130)
    at org.vaadin.spring.events.internal.ScopedEventBus.publish(ScopedEventBus.java:104)
    at org.vaadin.spring.events.internal.ScopedEventBus.publish(ScopedEventBus.java:111)
    at com.company.webApp.ui.presenter.SearchViewPresenter.getCustomer(SearchViewPresenter.java:42)
    at com.company.webApp.ui.viewImpl.SearchViewImpl$4.valueChange(SearchViewImpl.java:203)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508)