Issue Summary

Steps to Reproduce

1. Create a new user  (username lowercase only, like usera).
2. Create a new user (start with uppercase, like Userb).
3. Add a comment to a review with usera and Userb.
4. Go to Review Dashboard -> Search comments.
5. All comments are displayed.
6. Select comment author: usera and click Search.
7. Select comment author: Userb and click Search.

Expected Results

Ad 5. All comments (usera and Userb) are displayed. 

Ad 6. Comments by usera are displayed.

Ad 7. Comments by Userb are displayed.

Actual Results

Ad 5. As expected All comments (usera and Userb) are displayed. 

Ad 6. As expected (Comments by usera are displayed)

Ad 7. Comments by Userb are not displayed.

Notes

It seems like the username input for the filter is not changed to lowercase, whereas the search comment function indexes all comments authors in lower case.

Because of that, it tries to compare:

input_username == lower(comment_username)

instead of:

lower(input_username) == lower(comment_username).

(variables names made up just for illustration).

Please note it's a username that gets compared, not a display name. Changing the display name doesn't help.

Workaround

Change the username in URL itself after you click 'Search' to lower case only.