True; but to be fair, the text of Sporting Hero (Whiskey in the Jar / Bar) was based on the rather older Patrick Flemming, a genuinely Irish broadside song so far as we know: and it does contain some quotes from it. The situation is confused (in America) by Lovell, a related song presumably also based on Flemming, and by oral survivals of the latter which are often confused with Whiskey in the Jar because the stories are essentially the same.

Anyway, people who would like to know more should look at the previous discussion Q indicated earlier, where all that has already been gone into in greater detail. There isn't really a great deal of point in repeating here speculation which has already been addressed. Substantive new information on the song's history (as opposed to its modern commercial incarnations) would best go there as well.

Perhaps I should repeat Q's link. Origins: Whiskey In The Jar