Mentions should support finding users with a matching email address

Summary

The mention feature does not match on account email addresses. This makes it harder to find people you want to include in work on a ticket.

Compounding the problem, matches in the email address are bolded even though this is not used for the list of suggested users. See JRA-59230.

Environment

• Reproduced in JIRA 6.3.12, 6.3.15, 6.4.12

Steps to Reproduce

1. In a fresh JIRA installation create user accounts using the data in this list: mention-test-users.txt
2. Go to a JIRA issue and create a comment
3. Enter text "@jo" and observe which users are shown. Also note that "jo" at beginning of the email address is shown in bold like the matches in username and full name:
   
4. Add an "h" onto the @mention, e.g. "@joh".

Expected Results

The JEDY235544 account should be shown in the list of suggested users due to match on "johnston.cory@example.com".

Actual Results

The JEDY235544 account is not suggested, only the accounts where the first name, last name, or username start with "joh".

Notes

We can see that the REST calls are returning 10 users using a "contains" search. The JavaScript component searches within those results.

• mention-rest-jo.txt
• mention-rest-joh.txt

Suggested Solution

Make the @mention JavaScript component search on email addresses. option1-SearchEmail.patch.txt

In the meantime, we should stop bolding matches in the email address. option2-NoEmailBolding.patch.txt. See JRA-59230.

(I was unable to test the patches because I had trouble running JIRA from source. I hope they are helpful to illustrate the problem.)