[Bug]: Tags parented to each other causes TagStudio to freeze

[DMailbox]

Checklist

• I am using an up-to-date version.
• I have read the documentation.
• I have searched existing issues.

TagStudio Version

Alpha 9.5.1

Operating System & Version

Windows 11 OS Build 26100.3476

Description

Click the Add Tag button with a file selected, click the Manage Tags, or click Add Tag to Selected while the option is available causes TagStudio to stop responding. TagStudio worked without problems for about a day before this propblem started. I apologize for the lack of useful information.

Expected Behavior

When either of the buttons in the previous section are clicked the tag menu should open and the software should keep responding.

Steps to Reproduce

1. Open Tagstudio
2. Select or create a library
3. Click on a file thumnail
4. Click the Add Tag button

Logs

No response

[CyanVoxel]

What type of drive are you using? SSD? HDD? A networked drive? Does the program only temporarily not respond or does it permanently lock up?

[DMailbox]

I use an SSD. The program seems to permanently lock up although I have not left it to its own devices for more than about 30 minutes.

[CyanVoxel]

Hmm, interesting. Do you know if there's any file permission restrictions on the drive? Also if you have any hidden folders this might be related to #810

[DMailbox]

I am not trying to access any files in hidden folders. There are no unexpected restrictions or a need for permissions. I took some time to test a bunch of random stuff that I probably should have earlier, in doing this I found that only 1 folder is the problem however I do not know why. The problem folder is an Obsidian vault that has a folder with other Obsidian vaults inside of it. The previously mentioned vault is the only problematic folder, all other folders inside of it and outside of it work fine.

[DMailbox]

From some testing I found the problem is folder's ts_library.sqlite file, if it is removed and Tagstudio creates a new ts_library.sqlite file for the folder then Tagstudio works fine as far as I can tell. Attached is a zipped version of the problematic file, Github would not let me attach the normal version.

[CyanVoxel]

Thank you so much for the sample library, I'm now able to reproduce this issue even on macOS 15 👍
I'll investigate this further...

[CyanVoxel]

I've tracked down the cause. There are two tags "time" (ID:1011) and "dust" (ID:1024) that both have each other as parent tags. This is causing a recursive loop on line 951 of library.py where the program is asking the database to recursively select ancestor tags. The database query then gets stuck in a loop bouncing between 1011 and 1024.

This is no fault of your own doing - this is something that the program should not be allowing for in the first place, or at the very least it shouldn't be letting itself get into a loop like this. I'll tweak the issue title and bump the priority to critical.