Adding new labels to an attachment with versions duplicates the labels.

Steps to reproduce on clean confluence instance

1. Go to demonstration space
2. Click Tools - Attachments
3. Add attachment - any format (csv and ppt have been tested)
4. Label attachment with a label - any label
5. Use edit in office or attach file again to give two revisions.
6. Add another label
7. Refresh the page
   • You will now find that the initial label is duplicated, one for each revision, yet the new label only appears once.
8. Adding another label after this does not duplicate any of the existing labels.

NB: This issue no longer occurs for new labels created in Confluence 4.3.

However, any duplicated labels will still remain after upgrading. To remove them please follow the below steps:

1. Click the pen icon to edit the labels
2. Click on the X of one of the duplicated labels
   • This will make all labels of that word disappear, however it has only removed one. This is being tracked in CONF-26727
3. Close the label editor
4. Refresh the page
5. Repeat with all duplicated labels.