civicrm/civicrm-core — pull request #1112 by pratik-joshi (2013-07-04 13:58:29+00:00)
Title: CRM-12972 fix

This PR is for the DB error mentioned by the reporter.

this patch prevents producing a 'DB: already exists' which occurs when Pay pal sends ipn callback for a single (with same transaction id ) 'completed' recurring payment contribution more than once.