1 files changed, 52 insertions, 0 deletions
diff --git a/testsuite/tests/lib/IO/3307.hs b/testsuite/tests/lib/IO/3307.hs
new file mode 100644
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+++ b/testsuite/tests/lib/IO/3307.hs
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+import Control.Exception
+
+import System.Directory
+import System.Environment
+import System.IO
+
+import Data.Char
+import Data.List
+
+import GHC.IO.Encoding
+
+main = do
+    hSetBuffering stdout NoBuffering
+
+    -- 1) A file name arriving via an argument
+    putStrLn "Test 1"
+    [file] <- getArgs
+    print $ map ord file
+    readFile file >>= putStr
+
+    -- 2) A file name arriving via getDirectoryContents
+    putStrLn "Test 2"
+    [file] <- fmap (filter ("chinese-file-" `isPrefixOf`)) $ getDirectoryContents "."
+    print $ map ord file
+    readFile file >>= putStr
+
+    -- 3) A file name occurring literally in the program
+    -- The file is created with a UTF-8 file name as well, so this will only work in Windows or a
+    -- UTF-8 locale, or this string will be encoded in some non-UTF-8 way and won't match.
+    putStrLn "Test 3"
+    let file = "chinese-file-小说"
+    print $ map ord file
+    readFile file >>= putStr
+
+    -- 4) A file name arriving via another file.
+    -- Again, the file is created with UTF-8 contents, so we read it in that encoding.
+    -- Once again, on non-Windows this may fail in a non-UTF-8 locale because we could encode the valid
+    -- filename string into a useless non-UTF-8 byte sequence.
+    putStrLn "Test 4"
+    str <- readFileAs utf8 "chinese-name"
+    let file = dropTrailingSpace str
+    print $ map ord file
+    readFile file >>= putStr
+
+readFileAs :: TextEncoding -> FilePath -> IO String
+readFileAs enc fp = do
+    h <- openFile fp ReadMode
+    hSetEncoding h enc
+    hGetContents h
+
+dropTrailingSpace :: String -> String
+dropTrailingSpace = reverse . dropWhile (not . isAlphaNum) . reverse