mutli user - exception seen when user clicks on `restore` while viewing the revised version

1. Login using editor.
2. Open a document which is published. Take it offline and view one of the old version using `show revison history`
3. In another browser, login using author
4. Open the same document, edit (add or remove content) and request for publish
5. Go the editor browser, now click on restore. Attached exception is seen with below logs

01.09.2010 13:24:15 WARN [org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.invoke():136] Workflow call failed
org.hippoecm.repository.api.WorkflowException: unable to edit document with pending operation
at org.hippoecm.repository.reviewedactions.BasicReviewedActionsWorkflowImpl.obtainEditableInstance(BasicReviewedActionsWorkflowImpl.
java:117)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.hippoecm.repository.impl.WorkflowManagerImpl$WorkflowInvocationHandler.invoke(WorkflowManagerImpl.java:495)
at $Proxy2.obtainEditableInstance(Unknown Source)
at org.hippoecm.frontend.plugins.reviewedactions.VersionWorkflowPlugin$2.execute(VersionWorkflowPlugin.java:165)
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.execute(CompatibilityWorkflowPlugin.java:160)
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.execute(CompatibilityWorkflowPlugin.java:146)
at org.hippoecm.addon.workflow.CompatibilityWorkflowPlugin$WorkflowAction.invoke(CompatibilityWorkflowPlugin.java:134)