Issue Summary

If user's email address is used to add the user in a custom field User Picker (multiple users), the user won't be added to the custom field. This occurs when the user's email address and username are different, as if the username and email address are same, CSV import will add the user to the field.

Steps to Reproduce

1. Create a project (eg. Business project).
2. Add user A (ensure the username and email address are different).
3. Create a custom field (e.g "Test Multi User Picker") with User Picker (multiple users) type, and add it to screens (create/edit/view screens) of the project (step 1).
4. Use the following sample data to create issue using CSV Import (in below example, username is user and email address is user@example.com):

   Issue Type, Summary, Test Multi User Picker, Reporter
   Task, Test issue 1, user@example.com, user@example.com
   Task, Test issue 2, user, user@example.com
   

Expected Results

User with email address "user@example.com" be added to the custom field "Test Multi User Picker" in both issues

Actual Results

• In "Test issue 1" the user won't be added to the "Test Multi User Picker"
• However, in "Test issue 2" the user will be added to the field.

PS: This bug is applicable for both the Single user and Multi-user picker Custom Fields.

Workaround

Ensure to use username to add the user in custom field User Picker (multiple users)

PS: You cant apply this workaround if the username contains whitespaces, for this, see JRASERVER-67047