955. A Shopkeeper

135:21 If a Jew has wine deposited with a non-Jew, he is exempt from the mitzvah of succah both by day and by night. This is because it is necessary for him to make sure that the non-Jew does not touch the wine (which would render it yayin nesech). If something does not require watching, then one is obligated in the mitzvah of succah.

135:22 If a person stays in a shop - even if he lives outside of town and the shop is in town - and he is accustomed the rest of the year to eat in the shop by day most of the time, nevertheless he must eat in a succah on Succos.