Does the quick discharge of semen necessitate ghusl or just wudu'?

The emission of semen due to habitual desire necessitates ghusl (ritual bath). However, if it is emitted without habitual pleasure, ghusl is not required according to the Hanbalis, Malikis, and Hanafis, contrary to the Shafi'is. Ibn Qudamah argued that the Prophet, peace and blessings be upon him, described the semen that necessitates ghusl as being white and thick, and he said to Ali, "If the water gushes forth, then perform ghusl." Fadhkh (gushing forth) refers to its emission with force. In cases where ghusl is not obligatory, wudu' (ablution) is required, unless the emission of semen reaches the state of sals (incontinence).