"Mark as done" button doesn't clear all todos

Summary

I got a "mentioned" and "assigned" todo fro gitlab-com/Product#13597 (closed). I clicked the "mark as done" button in the header of the issue. It only cleared one todo. Is that expected?

Steps to reproduce

  1. Create an issue
  2. While creating the issue, assign it to a user AND mention them in the description
  3. This should generate 2 todos (assignment + mentioned)
  4. Have the user click the "Mark as done" button on the issue page

What is the current bug behavior?

  • Only one todo is resolved

What is the expected correct behavior?

  • Both todos should be resolved

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info 

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check 
(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)


(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)


(we will only investigate if the tests are passing)

Possible fixes