on [Pesachim] 59b rav Safra asks Rav a question about leaving the pesach korban overnight. Rav answers that rav Abba bar Chiyya already asked this question to rav Abahu.
There is a problem with this Gemara as rav Abahu was a talmid of rav Yochanan and so lived many years after Rav. Is there any other girsa?
Yes. The marginal note in most Gemaras asks your question and says that "Rav" should be changed to "Rava." This is also the Girsa of Rabeinu Chananel, and many of the Acharonim point this out as well (Melo ha'Ro'im, Mitzpeh Eisan, Tzelach, Seder ha'Doros, and Yefeh Einayim, and Dikdukei Sofrim).