On one of many Thomas Moore threads at Mudcat, a dear departed member asked after the tune to this lyric.
It is often cited under the title Nothing [In Life] Can Sadden Us.

The preceding title is the opening line of the first verse. However,
the song -- especially the tune -- was often cited by the opening line of the chorus, which is the thread title.

It seems that this was published under the pseudonym Thomas Little, and in retrospect Thomas Little is frequently identified as Thomas Moore. Anyone who knows anything more about the tune as such, is welcome to speak up, as the tune is new to me.

Future posts will contribute Moore a/k/a Little's song lyric, as well as other lyrics/parodies fitted to the same tune.

I have failed in my attempts, just now, to link to the page at tunearch.org/Wiki which lists this tune, without any lyrics.