Summary

Requesting GET /rest/api/2/workflow where query parameter workflowName's value is a non-existent workflow, Jira returns an HTTP 500 - Internal Server Error

Sample Call using HTTPie:

http --auth admin:admin --verbose GET http://localhost/jira/rest/api/2/workflow workflowName=="No such workflow"

Cause

Line 113 in WorkflowsResource.java:

String name = jiraWorkflow.getName();

If the workflow is not found, then jiraWorkflow will be null, and a NPE is thrown.