From a9ac58af31c1f793739da9ac9182438b107f184a Mon Sep 17 00:00:00 2001
From: konsumlamm <konsumlamm@gmail.com>
Date: Tue, 21 Jan 2025 19:37:21 +0100
Subject: [PATCH] Fix `Data.List.isInfixOf`

---
 lib/Data/List.hs   |  2 +-
 tests/ListTest.hs  | 12 +++++++-----
 tests/ListTest.ref |  1 +
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lib/Data/List.hs b/lib/Data/List.hs
index 354c7166..5c464ac5 100644
--- a/lib/Data/List.hs
+++ b/lib/Data/List.hs
@@ -336,7 +336,7 @@ isInfixOf :: forall a . Eq a => [a] -> [a] -> Bool
 isInfixOf = isInfixOfBy (==)
 
 isInfixOfBy :: forall a . (a -> a -> Bool) -> [a] -> [a] -> Bool
-isInfixOfBy eq cs ds = any (isPrefixOfBy eq cs) (inits ds)
+isInfixOfBy eq cs ds = any (isPrefixOfBy eq cs) (tails ds)
 
 splitAt :: forall a . Int -> [a] -> ([a], [a])
 splitAt n xs = (take n xs, drop n xs)
diff --git a/tests/ListTest.hs b/tests/ListTest.hs
index 6776b108..0f962b47 100644
--- a/tests/ListTest.hs
+++ b/tests/ListTest.hs
@@ -1,9 +1,11 @@
 module ListTest(module ListTest) where
-import Prelude
+
+import Data.List
 
 main :: IO ()
 main = do
-  putStrLn $ show $ sum [1,2,3::Int]
-  putStrLn $ show $ product [1,2,3,4::Int]
-  putStrLn $ show $ and [True]
-  putStrLn $ show $ and [True, False]
+  print $ sum [1, 2, 3 :: Int]
+  print $ product [1, 2, 3, 4 :: Int]
+  print $ and [True]
+  print $ and [True, False]
+  print $ [2] `isInfixOf` [1, 2, 3 :: Int]
diff --git a/tests/ListTest.ref b/tests/ListTest.ref
index dec1f87f..464add01 100644
--- a/tests/ListTest.ref
+++ b/tests/ListTest.ref
@@ -2,3 +2,4 @@
 24
 True
 False
+True