Nearly two decades before Harper Lee cautioned against killing mockingbirds in “To Kill a Mockingbird,” a New Orleans novelist pointed to the taboo about harming mockers in a book that’s now getting renewed attention, thanks to LSU Press.

“To Kill a Mockingbird,” of course, is all the rage again this summer, thanks to this month’s highly anticipated publication of “Go Set a Watchman,” the long-forgotten Lee novel that offers a different take on her legendary “Mockingbird” characters.

Lee’s 1960 work of fiction gets its title from a passage in which a small boy is warned against shooting mockingbirds with his air rifle. “Shoot all the blue jays you want, if you can hit’em,” he’s told. “Mockingbirds don’t do one thing but sing their hearts out for us. That’s why it’s a sin to kill a mockingbird.”

The reference invites lots of interpretations, but on one level, it can be read as an allegory for the way people tend to divide the world into stark terms of good or bad — the blue jays tagged as villains, the mockingbirds as a protected class. It’s a kind of thinking with obvious parallels to the racial prejudice Lee documents in “To Kill a Mockingbird.”

But the idea that mockingbirds shouldn’t be shot predates Lee’s story, as readers learn in the just-republished Southern comic novel “The Great Big Doorstep.” Written by New Orleans novelist E.P. O’Donnell, the book has achieved a small cult following since it was first published in 1941. O’Donnell was once considered one of the South’s most promising novelists, but his untimely death in 1943 obscured his legacy. Eudora Welty hailed O’Donnell’s “supreme gift” for dialogue and his “uncommon versatility,” but even so, few people have ever heard of “The Great Big Doorstep” — until now, at least.

LSU Press has just rereleased “The Great Big Doorstep” in a snazzy new paperback, bringing O’Donnell’s humorous tale of a Cajun family in Depression-era Louisiana to another generation of readers.

As the novel opens, the young Crochet sisters, Topal and Evvie, are hunting birds with a slingshot, hoping to trade their quarry with a local fisherman for coffee coupons they can redeem for housewares. The fisherman uses the birds for crab bait.

When Topal aims the slingshot at a mockingbird, Evvie urges her not to, but Topal follows through, missing her prize in the bargain. Then Evvie, more worried about besting her sister than keeping her principles, tries to kill the mockingbird, too. “The pebble slapped through the leaves and grazed the bird’s tail, dislodging feathers than spun downward,” O’Donnell tells readers. Even so, the mockingbird gets away.

But then Topal brings down a blue jay, adding the poor bird to her pile for the fisherman.

Did Harper Lee draw her mockingbird/blue jay imagery from this scene, if only subliminally? She would have been a teenager when O’Donnell’s first book appeared, although it was published just as America prepared to enter World War II. “The singularly inauspicious timing of what should have been O’Donnell’s breakout book meant it was lost to the tides of war,” says scholar Bryan Giemza in introducing the novel’s new edition.

Regardless of any connection it might have with Lee, “The Great Big Doorstep” can stand on its own. It’s equal parts Welty and Flannery O’Connor, with just a little P.G. Wodehouse thrown in. As Giemza writes of O’Donnell, he was a “man, ultimately, who could not resist a joke, least of all the larger jokes that life plays on us.”