Deleting a Page does not Delete its Draft

Summary of The Bug

When users deleting a page on Confluence, the draft won't be deleted with it at the same time. This cause a WARN stack trace on the log whenever a user editing another page which saved into a draft.

Here is the stack trace written on the logs:

2012-12-19 23:44:56,278 WARN [http-8090-4] [confluence.pages.actions.AbstractCreateAndEditPageAction] getCancelResult Removing invalid draft: Draft = { id: 851971, type: page, title: X, pageId: 851970}, for user : EmbeddedCrowdUser{name='admin', displayName='Septa Cahyadiputra', directoryId=294913} 
 -- url: /pages/doeditpage.action | userName: admin | referer: http://localhost:8090/pages/editpage.action?pageId=524292
com.atlassian.confluence.core.service.NotValidException: Page not found with id 851970

How to Replicate The Issue

1. Add a new page then save it
2. Edit the newly created page, wait until a draft was saved, then cancel editing
3. A draft version of the page is listed in "username drop down option" >> Drafts
4. Remove the page
5. Purge it from trash
6. Draft version of the page is still listed in "username drop down option" >> Drafts
7. Edit any other page, wait until a draft was saved, then cancel editing
8. atlassian-confluence.log will record the previously mentioned stack trace

Noted

Please note that the stack trace is a WARN message that does not affect Confluence usage as the draft of the new page is still saved

Workaround

There is a workaround detailed in this KB article. It involved finding and removing the orphans from the database.