This is reputed to be an 18th c. song. An oft-cited source is Chants et chansons populaires des provinces de l'ouest, Volume 1, p. 265 (with score), collected by Jérôme Bujeaud; Niort: L. Clouzot, 1866. I found the same lyrics and score in another journal dated 1863, so Bujeaud's work may have an earlier first printing date. Bujeaud collected the song in Poitou and Angoumois.

The lyrics there are, with the most minor differences, as Joe gave them above. The tune tallies with the "pop" versions, except that the first couplet was not repeated (though in some other 19th c. sources they are).

You will also see "Mon amant" for "Mon ami" and "O gué" for "O gai".

Clearly related is another old song about an orange-seller: "La marchande d'oranges". It has nearly the same metrical and structural pattern, a somewhat similar tune, and the same final line to each verse, "Vive la rose et le lilas."

Wikipedia has an article on "Vive la rose": click

On YouTube you can find sound clips of Emile Benoit (a brief one), Cristina Delume, Nana Mouskouri and probably others.