Does a person become a mushrik (one who associates partners with God) if he swears not to commit a sin, and states that if he does commit it, he is a mushrik, and then he falls into that sin?

A Muslim's statement, "If I do such-and-such, then I am a disbeliever, or a Jew, or a Christian," is a reprehensible and abhorrent oath. For in the Hadith: "Whoever swears by a religion other than Islam, lyingly, then he is as he said." The apparent meaning of the Hadith is that it renders the speaker a disbeliever, though it is possible that the intention is a threat. It is obligatory for the speaker to repent, seek forgiveness, and resolve not to return to such a statement again. His disbelief in this matter is a subject of scholarly disagreement.