Branch names with parentheses in them can't browse files

Summary

If you create a branch with parentheses in the name, then when you try to browse the files of that branch in the web UI, the list of files will be empty.

Steps to reproduce

1. Create branch from any other branch (e.g. master). Have name include parentheses, e.g. "test(foo)".
2. Click on Repository -> Files in the sidebar.
3. Note that no files are listed. Only the commit info from the HEAD commit for the branch is shown.

Example Project

What is the current bug behavior?

No files are shown

What is the expected correct behavior?

Files should be shown

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Results of GitLab application Check

Possible fixes