Conan search with channel broken

Summary

Searching for a conan package with a user and channel returns null instead of an empty list for results. When using conan search conan_package/*@user/stable I get ERROR: 'NoneType' object is not iterable. [Remote: gitlab]. This can be reproduced on the REST level:

Steps to reproduce

• curl "https://gitlab.com/api/v4/projects/25635002/packages/conan/v1/conans/search?q=conan_package/*@user/stable&ignorecase=False"

Example Project

https://gitlab.com/ptr-project/conan-packages

What is the current bug behavior?

curl returns {"results":null}

What is the expected correct behavior?

curl should return {"results":[]}

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Possible fixes

n/a