TrinityCore/TrinityCore — pull request #12084 by Trisjdc (2014-05-18 10:10:41+00:00)
Title: Core/Spells: Players with active pets count as if they were players in combat against spells with SPELL_ATTR1_CANT_TARGET_IN_COMBAT

Pretty well described in http://www.arenajunkies.com/topic/118924-combat-bug-with-pet/