Success deployment message is shown even if deployment failed

Describe the Bug When trying to deploy an invalid bpmn process the modeler shows the successful green message, but the process is not deployed and to understand what happened I have to check the camunda server logs.

Steps to Reproduce

Steps to reproduce the behavior:

Create the following process in the modeler:

<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" id="Definitions_1cdfxbw" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="2.2.4">
<bpmn:process id="BAD" isExecutable="true">
<bpmn:startEvent id="StartEvent_1">
  <bpmn:messageEventDefinition />
</bpmn:startEvent>
</bpmn:process>
<bpmndi:BPMNDiagram id="BPMNDiagram_1">
<bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="BAD">
  <bpmndi:BPMNShape id="StartEvent_0zki3qs_di" bpmnElement="StartEvent_1">
    <dc:Bounds x="173" y="102" width="36" height="36" />
  </bpmndi:BPMNShape>
</bpmndi:BPMNPlane>
</bpmndi:BPMNDiagram>
</bpmn:definitions>

Try to deploy via the "Deploy Current Diagram" button
You'll see the "Success" message, but comunda will just throw error:

21-Jan-2019 15:17:46.426 WARNING [http-nio-8080-exec-2] org.camunda.bpm.engine.rest.exception.ProcessEngineExceptionHandler.toResponse org.camunda.bpm.engine.ProcessEngineException: ENGINE-09005 Could not parse BPMN process. Errors:

attribute 'messageRef' is required | bad_diagram.bpmn | line 5 | column 38

Invalid 'messageRef': no message with id 'null' found. | bad_diagram.bpmn | line 5 | column 38

and nothing will be deployed

Expected Behavior

An error message w/ details should be shown instead of the success message.

Environment

Please complete the following information:

OS: Windows 10
Camunda Modeler Version: 2.2.4

camunda / camunda-modeler

Success deployment message is shown even if deployment failed #1123