From f7aebca12535aff8577e927e7f5bfc185c26e0c4 Mon Sep 17 00:00:00 2001
From: Mario Carneiro <di.gama@gmail.com>
Date: Fri, 16 Aug 2024 19:04:06 -0400
Subject: [PATCH] fix: splitAtD reverse bug from #919

---
 Batteries/Data/List/Basic.lean | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Batteries/Data/List/Basic.lean b/Batteries/Data/List/Basic.lean
index 7e6e034dc4..679e8c505d 100644
--- a/Batteries/Data/List/Basic.lean
+++ b/Batteries/Data/List/Basic.lean
@@ -137,7 +137,7 @@ def splitAtD (n : Nat) (l : List α) (dflt : α) : List α × List α := go n l
   if `splitAtD n l dflt = (left, right)`. -/
   go : Nat → List α → List α → List α × List α
   | n+1, x :: xs, acc => go n xs (x :: acc)
-  | 0, xs, acc => (acc, xs)
+  | 0, xs, acc => (acc.reverse, xs)
   | n, [], acc => (acc.reverseAux (replicate n dflt), [])
 
 /--