civicrm/civicrm-core — pull request #1830 by monishdeb (2013-10-22 10:19:05+00:00)
Title: CRM-13625 fix - Twitter text references thankyou page with session, not ...

As per the usage of url parameter for tweeting, it should pass url-encoded link otherwise it as in current situation it carries the current page url instead. For the same reason in our case it replaces with Event Thankyou page url. Still a minor issue persist as urlencoded & is not transformed back to & but & instead. Also replacing it with original symbol in url-encoded value is not of much help.

Reference: https://dev.twitter.com/docs/intents