revert recent bug fix temporarily for release

Decided this bug is not severe enough to delay the release until
tomorrow, so this will be re-applied after the release.

Git/Construct.hs

@@ -1,6 +1,6 @@
 {- Construction of Git Repo objects
  -
- - Copyright 2010-2023 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -23,7 +23,6 @@ module Git.Construct (
 	checkForRepo,
 	newFrom,
 	adjustGitDirFile,
-	isBareRepo,
 ) where
 
 #ifndef mingw32_HOST_OS
@@ -217,7 +216,7 @@ checkForRepo :: FilePath -> IO (Maybe RepoLocation)
 checkForRepo dir = 
 	check isRepo $
 		check (checkGitDirFile (toRawFilePath dir)) $
-			check (checkdir (isBareRepo dir)) $
+			check isBareRepo $
 				return Nothing
   where
 	check test cont = maybe cont (return . Just) =<< test
@@ -226,17 +225,16 @@ checkForRepo dir =
 		, return Nothing
 		)
 	isRepo = checkdir $ 
-		doesFileExist (dir </> ".git" </> "config")
+		gitSignature (".git" </> "config")
 			<||>
 		-- A git-worktree lacks .git/config, but has .git/gitdir.
 		-- (Normally the .git is a file, not a symlink, but it can
 		-- be converted to a symlink and git will still work;
 		-- this handles that case.)
-		doesFileExist (dir </>  ".git" </> "gitdir")
-
-isBareRepo :: FilePath -> IO Bool
-isBareRepo dir = doesFileExist (dir </> "config")
-	<&&> doesDirectoryExist (dir </> "objects")
+		gitSignature (".git" </> "gitdir")
+	isBareRepo = checkdir $ gitSignature "config"
+		<&&> doesDirectoryExist (dir </> "objects")
+	gitSignature file = doesFileExist $ dir </> file
 
 -- Check for a .git file.
 checkGitDirFile :: RawFilePath -> IO (Maybe RepoLocation)