No versions of an empty file

[phil-davis]

Steps to reproduce

1. make an empty file outside ownCloud touch xyz.txt
2. upload to ownCloud
3. edit the file (e.g. with files_texteditor) and put some text in it text 1111
4. edit the file and remove all the text (empty file)
5. edit the file (e.g. with files_texteditor) and put some text in it text 2222
6. look in file details, versions

Expected behaviour

3 old versions are seen - the file as it was at steps 2, 3 and 4

Actual behaviour

1 old version is seen - the version containing ```text 1111``

Server configuration

Development on core master

When a file is empty, then added to, the empty version is not saved.

This would impact on accurate recovery possibilities. e.g. if some software cares about a file that is used as a marker/lock indicator and can be empty or have something in it. "time machine" style of recovery should put versions back as they were, including if the file was empty in its old "incarnation".

[ownclouders]

GitMate.io thinks possibly related issues are #7708 (empty files do not create a version), #12044 (Can't detect existing file), #6708 (Edit no more impossible on a file), #10716 (File versions), and #8660 (Drag&drop is not working to upload files in an empty folder).

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 10 days if no further activity occurs. Thank you for your contributions.

[phil-davis]

Also, if you edit the file to be empty, then edit it again, then the empty version does not appear in the version history. It seems that the empty file is never added to to versions.

I will bet that there is an if ($someVariable != false) then saveVersion() somewhere in the code, and an empty file looks falsey.

This is still a problem.

[JammingBen]

Actually it behaves like this intentionally: https://github.com/owncloud/core/blob/issues/30657/apps/files_versions/lib/Storage.php#L180. When you create a new document with files_textviewer, it will be created as an empty document which then can be edited. Maybe this is the reason why there's no versions for empty files?

[phil-davis]

@pmaier1 what is the expected behavior if someone:

• upload text.txt with some content "first content"
• upload an empty file to text.txt (content is empty "")
• upload some other content to text.txt "some content"

Should there be 2 versions in the version history, with one of them being the empty file?