How do update fields from linked issue during transition

[Scott Federman]

When i transition from a status to "Dupe" status i request my user to select the duplicate bug using a custom issue picker field which automatically links the tickets using "is duplicate of" link type . When they do this i want it to copy certain fields from the linked issue to the current issue automatically. How would I do this?

[Ivan Tovbin]

A scripted post function seems to be the solution here. It will require a 3rd party addon however, like ScriptRunner, JMWE or Power Scripts.