From c837fdeb0df1652dcadcf712c565e30f79726091 Mon Sep 17 00:00:00 2001
From: Julian Brunner <julian.brunner@gmail.com>
Date: Sun, 27 Sep 2026 16:35:25 +0200
Subject: [PATCH 1/2] implement `readFile` in terms of `withFile` for prompt
 closing of handle

---
 src/Data/Text/IO.hs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/Data/Text/IO.hs b/src/Data/Text/IO.hs
index aa0e7faa..f4093e96 100644
--- a/src/Data/Text/IO.hs
+++ b/src/Data/Text/IO.hs
@@ -45,8 +45,7 @@ module Data.Text.IO
 import Data.Text (Text)
 import Prelude hiding (appendFile, getContents, getLine, interact,
                        putStr, putStrLn, readFile, writeFile)
-import System.IO (Handle, IOMode(..), openFile, stdin, stdout,
-                  withFile)
+import System.IO (Handle, IOMode(..), stdin, stdout, withFile)
 import qualified Control.Exception as E
 import Control.Monad (liftM2, when)
 import Data.IORef (readIORef)
@@ -73,7 +72,7 @@ import System.IO.Error (isEOFError)
 -- using 'Data.Text.Encoding.decodeUtf8' '.' 'Data.ByteString.readFile'
 -- is a much faster and safer alternative.
 readFile :: FilePath -> IO Text
-readFile name = openFile name ReadMode >>= hGetContents
+readFile name = withFile name ReadMode hGetContents
 
 -- | Write a string to a file.  The file is truncated to zero length
 -- before writing begins.

From 0ef79eeb4771acb57f342e889ac7b8aedb741f37 Mon Sep 17 00:00:00 2001
From: Li-yao Xia <lysxia@gmail.com>
Date: Wed, 7 Oct 2026 00:34:24 +0200
Subject: [PATCH 2/2] Add regression test: readFile must close the handle on
 exception

---
 tests/Tests/Regressions.hs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/Tests/Regressions.hs b/tests/Tests/Regressions.hs
index 892d635d..64a31fe6 100644
--- a/tests/Tests/Regressions.hs
+++ b/tests/Tests/Regressions.hs
@@ -13,6 +13,7 @@ module Tests.Regressions
 import Control.Exception (ErrorCall, SomeException, handle, evaluate, displayException, try)
 import Data.Char (isLetter, chr)
 import GHC.Exts (Int(..), sizeofByteArray#)
+import Control.Exception (IOException)
 import System.IO
 import System.IO.Temp (withSystemTempFile)
 import Test.Tasty.HUnit (assertBool, assertEqual, assertFailure, (@?=))
@@ -36,6 +37,8 @@ import qualified Test.Tasty as F
 import qualified Test.Tasty.HUnit as F
 import Tests.Utils (withTempFile)
 import System.IO.Error (isFullError)
+import Control.Monad (when)
+import Data.Either (isRight)
 
 -- Reported by Michael Snoyman: UTF-8 encoding a large lazy bytestring
 -- caused either a segfault or attempt to allocate a negative number
@@ -213,6 +216,17 @@ t648 = withTempFile $ \_ h -> do
   line' <- T.hGetLine h
   T.append line "\r" @?= line'
 
+t714 :: IO ()
+t714 = withTempFile $ \name h -> do
+  hSetBinaryMode h True
+  hPutChar h '\xFF'
+  hClose h
+  e :: Either IOException T.Text <- try (T.readFile name)
+  when (isRight e) (assertFailure "should fail")
+  -- readFile must close the handle even in the case of an exception,
+  -- in which case the next line should succeed.
+  openFile name WriteMode >>= hClose
+
 tests :: F.TestTree
 tests = F.testGroup "Regressions"
     [ F.testCase "hGetContents_crash" hGetContents_crash
@@ -233,4 +247,5 @@ tests = F.testGroup "Regressions"
     , F.testCase "t559" t559
     , F.testCase "t633" t633
     , F.testCase "t648" t648
+    , F.testCase "t714" t714
     ]