Bulk adding tags can create "duplicate" posts_tags rows

[brvnnghi]

Issue Summary

Tag count doubled when adding an existing tag in a post again via Context Menu.

The correct behaviour would be, if a tag is already existed in a post, it should not be tagged again using "Add a Tag" in Context Menu.

Steps to Reproduce

1. Create new tag
2. Tag inside a post
3. Tag again using Context Menu ("Add a tag")
4. See tag count = 2 when there's only 1 post

Ghost Version

5.94

Node.js Version

22

How did you install Ghost?

Linux / Local

Database type

MySQL 8

Browser & OS version

No response

Relevant log / error output

No response

Code of Conduct

• I agree to be friendly and polite to people in this repository

[kevinansfield]

Thank you for the report.

The problem code is located here. PRs are welcome 🙂

Aside from the double counting the duplicate post_id+tag_id rows in the posts_tags table does not appear to cause any other issues. Deleting the attached tag from the UI correctly deletes both rows.

If you're aware of any other problems this causes please elaborate.

As for the fix there are two approaches:

1. Add a check to the bulk edit feature to skip inserting duplicate rows
2. Add a unique index across the posts_tags.{post_id,tag_id} columns so data integrity is ensured at the database level (this will likely also require approach 1 or a similar handling of errors during the insert, as well as a migration to remove duplicates before the unique index is added)