Hope the following helps. It looks like the folder names are some sort of checksum that includes the file contents and its full path. Let me know if you need anything more.<br><br>
Test 1
Add myslides.pptx to library
- folder 39bfe32b05807062df604ba7024d4a34 appears in data/presentations/thumbnails
Add myslides.pptx to service plan
- nothing changes in thumbnails
Send it to live
- folder c45c4389c3a7bb8a3ea0aebc21b2d50e appears in thumbnails
Send something else to live and remove myslides.pptx from plan
- nothing changes in thumbnails
Delete myslides.pptx from library
- 39bfe32b05807062df604ba7024d4a34 is deleted from thumbnails but c45c4389c3a7bb8a3ea0aebc21b2d50e remains
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Test 2
Add myslides.pptx (same file) to library again
- folder 39bfe32b05807062df604ba7024d4a34 reappears in data/presentations/thumbnails
Add to service plan and send to live
- nothing changes, ie both folders still there
Remove from service plan, delete from library, close OpenLP
- c45c4389c3a7bb8a3ea0aebc21b2d50e remains
<br>
Test 3
Repeat Test 2 after quitting and restarting OpenLP
Same result as Test 2
<br>
Test 4
Repeat Test 2 but opened copy of myslides.pptx from a different location
- folder c0a8a8d07494b601675613495be4ec6f appears
Add to service plan and sent to live
- folder 45145f6cc5b7b83b4a426285a3cdc9a4 appears
Remove from service plan and delete from library
- folder c0a8a8d07494b601675613495be4ec6f disappears (c45c... and 4514... remain)
<br>
Test 5
Changed content of myslides.pptx in same location as test 4, added to library
- folder c0a8a8d07494b601675613495be4ec6f appears
Add to service plan and send to live
- no new folder appears, but 45145f6cc5b7b83b4a426285a3cdc9a4 has been updated (timestamp updated)
<br>