Add a test for reliable encoding errors

testsuite/tests/ghc-regress/lib/IO/all.T

@@ -156,3 +156,5 @@ test('openTempFile001', normal, compile_and_run, [''])
 test('T4113', normal, compile_and_run, [''])
 
 test('T4144', normal, compile_and_run, [''])
+
+test('encodingerror001', normal, compile_and_run, [''])

testsuite/tests/ghc-regress/lib/IO/encodingerror001.hs

+import System.IO
+import System.IO.Error
+import Text.Printf
+import Control.Monad
+
+main = do
+  hSetEncoding stdout latin1
+  forM [NoBuffering,
+        LineBuffering,
+        BlockBuffering Nothing,
+        BlockBuffering (Just 3),
+        BlockBuffering (Just 9),
+        BlockBuffering (Just 32)] $ \b -> do
+     hSetBuffering stdout b
+     checkedPutStr "test 1\n"
+     checkedPutStr "ě\n" -- nothing gets written
+     checkedPutStr "test 2\n"
+     checkedPutStr "Hέllo\n" -- we should write at least the 'H'
+     checkedPutStr "test 3\n"
+     checkedPutStr "Hello αβγ\n" -- we should write at least the "Hello "
+
+checkedPutStr str = do
+  r <- try $ putStr str
+  case r of
+    Right _ -> return ()
+    Left  e -> printf "Caught %s while trying to write %s\n"
+                  (show e) (show str)

testsuite/tests/ghc-regress/lib/IO/encodingerror001.stdout

+test 1
+Caught <stdout>: hPutChar: invalid argument (character is out of range for this encoding) while trying to write "\283\n"
+test 2
+HCaught <stdout>: hPutChar: invalid argument (character is out of range for this encoding) while trying to write "H\941llo\n"
+test 3
+Hello Caught <stdout>: hPutChar: invalid argument (character is out of range for this encoding) while trying to write "Hello \945\946\947\n"
+test 1
+Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "\283\n"
+test 2
+HCaught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "H\941llo\n"
+test 3
+Hello Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "Hello \945\946\947\n"
+test 1
+Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "\283\n"
+test 2
+HCaught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "H\941llo\n"
+test 3
+Hello Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "Hello \945\946\947\n"
+test 1
+Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "\283\n"
+test 2
+HCaught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "H\941llo\n"
+test 3
+Hello Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "Hello \945\946\947\n"
+test 1
+Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "\283\n"
+test 2
+HCaught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "H\941llo\n"
+test 3
+Hello Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "Hello \945\946\947\n"
+test 1
+Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "\283\n"
+test 2
+HCaught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "H\941llo\n"
+test 3
+Hello Caught <stdout>: commitBuffer: invalid argument (character is out of range for this encoding) while trying to write "Hello \945\946\947\n"