Confluence index floods the temp folder with tmp files from pptx files

Confluence reindex produces one com.atlassian.confluence.extra.officeconnector.index.powerpoint.PowerPointXMLTextExtractorxxxxxxxxxxxxxxxxxxx.tmp for each pptx file attached to the instance.

Each reindex creates a new tmp files and leaves the older one there (conf_install/temp), without cleaning it. This can leave a huge garbage in confluence temp folder as we can see in the example below.

The file used for this test was a empty pptx file and it's attached to this issue for testing purposes.

Replication steps

1. Install Confluence 5.7 standalone
2. Login to Confluence 5.7
3. Download the empty.pptx and save it on my desktop
4. Create a new Space named test
5. Click on the edit button on the home space to enter edit mode
6. Drag the empty.pptx from my desktop to the space home page and then click on "Save" button
7. Navigate to the folder <confluence_installation_directory>/temp
8. You can see a new entry is created on Confluence installation temp folder

Workaround

Disable the index of PPT and PPTX files for now as stated here.