Cambridge: past tense and past participle : here is the cambridge link:spat.https://dictionary.cambridge.org/dictionary/english/spit#british-1-1-2
Oxford:spits, spitting, spat, spitted Oxford link :https://en.oxforddictionaries.com/definition/spit
Collins:spits, spitting, spat or spit Word forms: spits, spitting or spitted Collins link:https://www.collinsdictionary.com/dictionary/english/spit
Wikitionary:spitted,spitted spat/spit,spat/spit https://en.wiktionary.org/wiki/spit
Which one is correct?