Is "des" a preposition + article in "Il se versait des petits verres"?

Question

The question is on the last sentence of this passage from Flaubert's L'Éducation sentimentale.

Des arbres la couronnaient parmi des maisons basses couvertes de toits à l’italienne. Elles avaient des jardins en pente que divisaient des murs neufs, des grilles de fer, des gazons, des serres chaudes, et des vases de géraniums, espacés régulièrement sur des terrasses où l’on pouvait s’accouder. Plus d’un, en apercevant ces coquettes résidences, si tranquilles, enviait d’en être le propriétaire, pour vivre là jusqu’à la fin de ses jours, avec un bon billard, une chaloupe, une femme ou quelque autre rêve. Le plaisir tout nouveau d’une excursion maritime facilitait les épanchements. Déjà les farceurs commençaient leurs plaisanteries. Beaucoup chantaient. On était gai. Il se versait des petits verres.

Question

Which way of understanding the sentence is correct.

1. Il refers to on of the previous sentence. se is an indirect object (or, as it were, in the "dative case"). des is an indefinite article.

2. Il refers to on of the previous sentence. se is a direct object (or in the "accusative"). des is made of de and les, i.e. a preposition and a definite article.

3. Il is an impersonal pronoun. se turns the voice of the verb to passive (or "middle"). des is made of de and les, i.e. a preposition and a definite article.

I have added 3 because of this answer to another (related) post.

Background

If you think 3 is correct (at least to the extent of Il being an impersonal pronoun and not a substitute for on), please also see this this related post, in which I assume that (i.e. Il being an impersonal pronoun) and ask further questions.

If, on the other hand, you think 1 or 2 is correct, you may want to give me answer in this post to such effect. Thanks.

Answer 1

Il is an impersonal pronoun. se doesn't turn the voice to passive, but is present as part of the idiomatic construction "il se [verb]" in which il is an impersonal pronoun; the idiom isn't a passive voice construction, but can roughly be translated to English passive voice. des is not the contraction of de les here but an indefinite article.