What is the ruling on drinking while standing in the mosque out of necessity, or leaving the mosque to drink while sitting to avoid missing the time of the Adhan after performing the two rak'ahs for greeting the mosque?

If there is ample time such that one does not fear missing the Adhan, then it is recommended to begin with the salutation of the mosque (Tahiyyat al-Masjid), then drink, then give the Adhan. However, if one fears missing the Adhan by performing the salutation of the mosque, then it is legislated to drink while standing, then give the Adhan.