Adding a group as a reviewer fails when the group id contains special characters because is not encoded

Summary

Groups containing special characters (e.g. # or /) cannot be added as Reviewers.

Steps to Reproduce

1. Create a group with a special character in it in an external user directory (e.g. JIRA or LDAP)
2. Synchronize the group to FishEye
3. Add the groups as a reviewer to a review

Expected Results

The users belonging to the group are added as reviewer.

Actual Results

The users are not added as reviewer, and the following message is displayed in the user interface:

Failed to fetch group members. Check Internet connection or contact your administrator.

Notes

Groups with special characters cannot be created directly in FishEye, they can only be imported by and external user directory.
When attempting to create a group with special characters in FishEye, the following message is shown:

Group name can only contain alphanumeric, underscore, at ('@'), dot, dash or backslash

A call for group with id //// will result in following request call:
<FISHEYE_URL>/rest-service/reviewer-search/CR-3/groups///////members

A call for group with id starting with # will result in following request call:
<FISHEYE_URL>/fisheye/rest-service/reviewer-search/CR-27/groups/

The following is an expected request call:
<FISHEYE_URL>/fisheye/rest-service/reviewer-search/CR-27/groups/<group_name>/members

Workaround

No workaround is currently available.