Does divorce occur if the son eats from food that the husband forbade eating from, after the husband conditioned his wife's divorce upon that with the intention of disciplishing the son?

Anger does not prevent the occurrence of divorce unless it reaches the point of incapacitating the mind. A conditional divorce takes effect when the condition is met, whether the husband intended to enact the divorce or merely to threaten, and this is the fatwa we adhere to. However, Sheikh Al-Islam Ibn Taymiyyah holds that a conditional divorce intended as a threat or emphasis is treated like an oath, and the husband must pay an expiation for breaking an oath when the condition is met, and the divorce does not occur. Accordingly, if you make the child eat from the forbidden food, you will be divorced according to the fatwa we adhere to. As for Ibn Taymiyyah's view, the divorce does not occur, and your husband must pay an expiation for an oath if he did not intend divorce but rather emphasis and prohibition.