Jira stops project import after failing to create a non-mandatory user

Problem Experienced

During a project import, Jira treats non-mandatory users just like the mandatory ones and will fail if it's unable to create them.

Existing Behavior:

If Jira fails to create at least 10 non-mandatory users during a project import, the process stops with a failure.

Expected Behavior

Jira logs/informs the user via UI about problems with creating the non-mandatory users, but it continues the operation. It fails only when the users are mandatory to the process.

Notes
Inside DefaultProjectImportManager#createMissingUsers Jira tries to create all of the missing users. It doesn't differentiate between mandatory and non-mandatory users.
It gets the users from UserMapper#getUsersToAutoCreate that gets the mandatory and non-mandatory users separately.

The bug can be fixed by either:

• returning only the mandatory users from the getUsersToAutoCreate method (or actually creating a new method with that behaviour since this method is used in a few more places), or
• indicating which users are mandatory and which are not and increasing the failure count only for the former.