For some notes, note history is available but all entries show blank contents in the UI

[mrjo118]

Operating system

Windows

Joplin version

3.3.4

Desktop version info

No response

Current behaviour

A user has stated: "In Joplin in Windows in note history in the note properties I see the previous versions, but when I select a date, it doesn't show any text, and when I recover it all I get is a blank note."
See https://discourse.joplinapp.org/t/recovering-erased-note/44862/

I think there is a potential issue with note history normalisation here. I too have seen this issue before and have it with one of my current notes. It may be related to changing a large amount, or possibly the entire note content in one go. Because for the note that it is affecting, I replace the entire contents from a local txt file whenever I make updates to it.

I have a short note history ttl of 3 days set, but I have 3 revisions for the note currently, and for all of the revisions for this note when selected from the UI, they show the contents as completely blank. For the note in question, it is 133,087 characters long

Looking at the 3 matching entries for the note id in the revisions table of the sqlite db, I can confirm that none of the revision entries contain the full note at the relevant state in time, but they only have the recent changes

Expected behaviour

When revisions are updated / deleted, there should always remain one revision entry which includes a snapshot of the full note at the point where the note history is cut off. The note history preview and restoration should also work correctly for all notes where revisions are available, rather than displaying empty note contents

Logs

No response