Project search API endpoint crashes on special character searches

Summary

The project search API endpoint (/search?scope=project) does not handle certain special characters very well, leading to server (timeout?) errors.

Steps to reproduce

Make an authenticated API request:

https://gitlab.com/api/v4/search?scope=projects&search=ß😃☀♴&per_page=1&pages=1

Or just hit this to get a 500 on gitlab.com:

https://gitlab.com/search?utf8=✓&snippets=&scope=&search=ß😃☀♴

Example Project

Not applicable. Happens on gitlab.com

What is the current bug behavior?

Crash / hang.

What is the expected correct behavior?

Most likely an empty 200 result [].

Relevant logs and/or screenshots

No logs returned. Typically 502, 500, or timeout response.

Output of checks

This bug happens on GitLab.com

Possible fixes