CLONE -Custom field request: resolver

It would be useful if one could have a read-only custom field for the "resolver" of an issue. Ie, the user who changed the "resolution" field to something non-null. From jira-user:

> Is there a way to search for a resolver of an issue?
> Our developers report for example which classes are changed by a fix and
> then assign the issue to Quality Assurance.
> Later they have to apply this fix on older versions of our program and
> would like to find again the issues they worked on.