Problem with online conflict resolution and editing

Summary

I can't resolve the merge conflict using either the Interactive mode, by choosing Use ours or Use theirs buttons.

Steps to reproduce

When the character "" exists in the conflicting file,I can't resolve the merge conflict using either the Interactive mode, by choosing Use ours or Use theirs buttons. image image

Under what conditions will the code reach this if statement? https://gitlab.com/rluna-gitlab/gitlab-ce/-/blob/master/lib/gitlab/git/conflict/parser.rb#L44 image

Example Project

What is the current bug behavior?

What is the expected correct behavior?

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