Cannot Complete Tasks on Issues with Embedded Code Task Templates

Summary

When an issue with tasks has a code block that is a different task template, tasks below the code block are unable to be completed.

Steps to reproduce

1. Create an issue with this:

• Task 1
• Task 2

  - [ ] Template task 1
    - [ ] template sub-task 1
  - [ ] template task 2
    - [ ] template sub-task 2

• Task 3
• Task 4

2. Mark Task 3 complete

Example Project

kwiebers/test-repo#2

What is the current bug behavior?

Banner error of "Someone edited this issue at the same time you did. The description has been updated and you will need to make your changes again."

What is the expected correct behavior?

Task 3 is marked as completed

Relevant logs and/or screenshots

I receive a 409 error from PATCH https://gitlab.com/kwiebers/test-repo/issues/2.json with this payload when completing Task 3:

{"issue":{"description":"* [ ]  Task 1\n* [ ]  Task 2\n  ```\n  - [x] Template task 1\n    - [ ] template sub-task 1\n  - [ ] template task 2\n    - [ ] template sub-task 2\n  ```\n* [ ]  Task 3\n* [ ]  Task 4","lock_version":0,"update_task":{"index":3,"checked":true,"line_number":4,"line_source":"  - [ ] Template task 1"}}}

The Index and identified task is within the template and not Task 3.

Output of checks

This bug happens on GitLab.com

Possible fixes

I'll look into where to fix this but my workaround for my team on-boarding issue is move that template to the bottom and everything worked fine.