Workflow Scheme with Bad Workflow Cannot be Disassociated from Project

A workflow scheme that uses a "bad workflow" (contains Status ID error introuduced via XML import) cannot be unhooked from a project. The "Actions Cog" is missing from the workflow tab so it's not possible to switch to a different scheme and undo the damage.

The bad workflow cannot be deleted because it is active.
The workflow scheme cannot be edited or deleted because it is active.

There are three fixes, all rather extreme:

1. Roll back: restore JIRA from back-up
2. Make changes to the JIRA database to edit the Status ID
3. Delete the project & then re-import the XML workflow after fixing the Status ID there.

I believe that it's a defect that there is no way to switch to a different workflow scheme.

Background:

An XML workflow that has been massaged to contain good "fieldscreen.id" can be imported into JIRA without generating an exception on import.

However, if the XML contains an invalid "status.id" then the import will appear to succeed without problems.

If the workflow is then associated with a workflow scheme and that scheme associated with a project then an exception will display on-screen when viewing the workflow tab for the project admin:

Error rendering WebPanel (workflows/workflows.vm): org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getHtml' in class com.atlassian.jira.web.component.IssueConstantWebComponent threw exception java.lang.NullPointerException at workflows/workflows.vm[line 136, column 65]

From atlassian-jira.log:

2012-05-11 14:01:18,815 http-8080-13 WARN marks 841x388766x1 17d4esl 192.168.150.57 /plugins/servlet/project-config/TST/workflows [plugin.web.model.ResourceTemplateWebPanel] Error rendering WebPanel (workflows/workflows.vm): org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getHtml' in  class com.atlassian.jira.web.component.IssueConstantWebComponent threw exception java.lang.NullPointerException at workflows/workflows.vm[line 136, column 65]
com.atlassian.templaterenderer.RenderingException: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getHtml' in  class com.atlassian.jira.web.component.IssueConstantWebComponent threw exception java.lang.NullPointerException at workflows/workflows.vm[line 136, column 65]
	at com.atlassian.templaterenderer.velocity.one.six.internal.VelocityTemplateRendererImpl.render(VelocityTemplateRendererImpl.java:100)
	at com.atlassian.templaterenderer.AbstractVelocityWebPanelRenderer.render(AbstractVelocityWebPanelRenderer.java:33)
	at com.atlassian.plugin.web.model.ResourceTemplateWebPanel.getHtml(ResourceTemplateWebPanel.java:47)
(snip..see attached log)

Note Also:

There might be two other issues here..

1. The XML import should check Status ID
2. Integrity Checker should check Status ID. This is what it gives currently when there is a workflow with a broken Status ID:

Check Workflow Integrity
PASSED: Check workflow entry states are correct
PASSED: Check workflow current step entries
PASSED: Check JIRA issues with null status