git-repair (1.20131122) unstable; urgency=low

  * Added test mode, which can be used to randomly corrupt test
    repositories, in reproducible ways, which allows easy
    corruption-driven-development.
  * Improve repair code in the case where the index file is corrupt,
    and this hides other problems.
  * Write a dummy .git/HEAD if the file is missing or corrupt, as
    git otherwise will not treat the repository as a git repo.
  * Improve fsck code to find badly corrupted objects that crash git fsck
    before it can complain about them.
  * Fixed crashes on bad file encodings.
  * Can now run 10000 tests (git-repair --test -n 10000 --force)
    with 0 failures.

# imported from the archive

1 files changed, 59 insertions, 0 deletions

diff --git a/Utility/Exception.hs b/Utility/Exception.hs
new file mode 100644
index 0000000..cf2c615
--- /dev/null
+++ b/Utility/Exception.hs
@@ -0,0 +1,59 @@
+{- Simple IO exception handling (and some more)
+ -
+ - Copyright 2011-2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE ScopedTypeVariables #-}
+
+module Utility.Exception where
+
+import Control.Exception
+import qualified Control.Exception as E
+import Control.Applicative
+import Control.Monad
+import System.IO.Error (isDoesNotExistError)
+import Utility.Data
+
+{- Catches IO errors and returns a Bool -}
+catchBoolIO :: IO Bool -> IO Bool
+catchBoolIO a = catchDefaultIO False a
+
+{- Catches IO errors and returns a Maybe -}
+catchMaybeIO :: IO a -> IO (Maybe a)
+catchMaybeIO a = catchDefaultIO Nothing $ Just <$> a
+
+{- Catches IO errors and returns a default value. -}
+catchDefaultIO :: a -> IO a -> IO a
+catchDefaultIO def a = catchIO a (const $ return def)
+
+{- Catches IO errors and returns the error message. -}
+catchMsgIO :: IO a -> IO (Either String a)
+catchMsgIO a = either (Left . show) Right <$> tryIO a
+
+{- catch specialized for IO errors only -}
+catchIO :: IO a -> (IOException -> IO a) -> IO a
+catchIO = E.catch
+
+{- try specialized for IO errors only -}
+tryIO :: IO a -> IO (Either IOException a)
+tryIO = try
+
+{- Catches all exceptions except for async exceptions.
+ - This is often better to use than catching them all, so that
+ - ThreadKilled and UserInterrupt get through.
+ -}
+catchNonAsync :: IO a -> (SomeException -> IO a) -> IO a
+catchNonAsync a onerr = a `catches`
+	[ Handler (\ (e :: AsyncException) -> throw e)
+	, Handler (\ (e :: SomeException) -> onerr e)
+	]
+
+tryNonAsync :: IO a -> IO (Either SomeException a)
+tryNonAsync a = (Right <$> a) `catchNonAsync` (return . Left)
+
+{- Catches only DoesNotExist exceptions, and lets all others through. -}
+tryWhenExists :: IO a -> IO (Maybe a)
+tryWhenExists a = eitherToMaybe <$>
+	tryJust (guard . isDoesNotExistError) a