Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) said: Laughing in prayer does not require the ablution to be repeated.
Abu Shaybah Ibrahim bin Uthman narrated it from Yazid Abu Khalid as a saying of the Prophet (marfu'); Abu Shaybah is da'if (weak), and the correct view is that it is mawquf (a saying of the Companion).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 675