Prevent JIRA from creating duplicate draft workflows

Expected Behaviour

JIRA should automatically detect duplicated drafts of workflows and delete the duplicate.

Actual Result

When the creation of a duplicated draft of a workflow occurs in the database, trying to edit the workflow or create another draft results in 500 errors.

Steps to reproduce

It's not certain how to reproduce this or what exactly causes the duplication of the drafts.

There's some hints on the cause being around concurrent uses of the workflows' editing feature. However, a test recently performed on our side returned no more than some 404 errors when two people were editing the same workflow.

Diagnosis

Run the below query to find out whether you have duplicated drafts or not and also what workflows are affected by this.

SELECT
	COUNT(*) AS	"# of Drafts",
	parentname AS "Workflow",
	MAX(id) AS "Duplicate" 
FROM
	jiradraftworkflows
GROUP BY 
	parentname 
HAVING 
	count(*) > 1;

Workaround

Run the below query to delete the duplicated drafts.

Make sure you have an up-to-date backup of JIRA's database before performing any manual data manipulation.

DELETE FROM jiradraftworkflows WHERE id IN (
	SELECT max(id) FROM jiradraftworkflows GROUP BY parentname HAVING count(*) > 1)