Restore return type of toLinkTarget to Maybe LinkTarget for the sake of backward compatibility

Author: Bodigrim

Codec/Archive/Tar/Check/Internal.hs

@@ -40,7 +40,6 @@ module Codec.Archive.Tar.Check.Internal (
 import Codec.Archive.Tar.LongNames
 import Codec.Archive.Tar.Types
 import Control.Applicative ((<|>))
-import Control.Monad.Catch (MonadThrow(throwM))
 import qualified Data.ByteString.Lazy.Char8 as Char8
 import Data.Maybe (fromMaybe)
 import Data.Typeable (Typeable)

Codec/Archive/Tar/Types.hs

@@ -53,7 +53,6 @@ module Codec.Archive.Tar.Types (
 
   LinkTarget(..),
   toLinkTarget,
-  toLinkTarget',
   fromLinkTarget,
   fromLinkTargetToPosixPath,
   fromLinkTargetToWindowsPath,
@@ -78,7 +77,6 @@ import qualified Data.ByteString.Char8 as BS.Char8
 import qualified Data.ByteString.Lazy  as LBS
 import Control.DeepSeq
 import Control.Exception (Exception, displayException)
-import Control.Monad.Catch (MonadThrow, throwM)
 
 import qualified System.FilePath as FilePath.Native
          ( joinPath, splitDirectories, addTrailingPathSeparator, hasTrailingPathSeparator, pathSeparator, isAbsolute, hasTrailingPathSeparator )
@@ -489,11 +487,12 @@ instance NFData LinkTarget where
 -- | Convert a native 'FilePath' to a tar 'LinkTarget'.
 -- string is longer than 100 characters or if it contains non-portable
 -- characters.
-toLinkTarget   :: MonadThrow m => FilePath -> m LinkTarget
-toLinkTarget path | length path <= 100 = do
-                                           target <- toLinkTarget' path
-                                           pure $! LinkTarget (packAscii target)
-                  | otherwise          = throwM (TooLong path)
+toLinkTarget :: FilePath -> Maybe LinkTarget
+toLinkTarget path
+  | length path <= 100 = do
+    target <- toLinkTarget' path
+    Just $! LinkTarget (packAscii target)
+  | otherwise = Nothing
 
 data LinkTargetException = IsAbsolute FilePath
                          | TooLong FilePath
@@ -505,10 +504,10 @@ instance Exception LinkTargetException where
 
 -- | Convert a native 'FilePath' to a unix filepath suitable for
 -- using as 'LinkTarget'. Does not error if longer than 100 characters.
-toLinkTarget' :: MonadThrow m => FilePath -> m FilePath
+toLinkTarget' :: FilePath -> Maybe FilePath
 toLinkTarget' path
-  | FilePath.Native.isAbsolute path = throwM (IsAbsolute path)
-  | otherwise = pure $ adjustDirectory $ FilePath.Posix.joinPath $ FilePath.Native.splitDirectories path
+  | FilePath.Native.isAbsolute path = Nothing
+  | otherwise = Just $ adjustDirectory $ FilePath.Posix.joinPath $ FilePath.Native.splitDirectories path
   where
     adjustDirectory | FilePath.Native.hasTrailingPathSeparator path
                     = FilePath.Posix.addTrailingPathSeparator

tar.cabal

@@ -48,13 +48,12 @@ library
 
 library tar-internal
   default-language: Haskell2010
-  build-depends: base       >= 4.11.0.0  && < 5,
+  build-depends: base       >= 4.11  && < 5,
                  array                 < 0.6,
                  bytestring >= 0.10 && < 0.13,
                  containers >= 0.2  && < 0.8,
                  deepseq    >= 1.1  && < 1.6,
                  directory  >= 1.3.1 && < 1.4,
-                 exceptions,
                  filepath              < 1.5,
                  time                  < 1.13
 
@@ -88,7 +87,7 @@ library tar-internal
 test-suite properties
   type:          exitcode-stdio-1.0
   default-language: Haskell2010
-  build-depends: base,
+  build-depends: base < 5,
                  array,
                  bytestring >= 0.10,
                  containers,
@@ -131,7 +130,7 @@ benchmark bench
   default-language: Haskell2010
   hs-source-dirs: bench
   main-is:       Main.hs
-  build-depends: base,
+  build-depends: base < 5,
                  tar,
                  bytestring >= 0.10,
                  filepath,