Fix cleanup when stdin/stdout handles are inherited and are Nothing

Author: pranaysashank

src/Streamly/Internal/System/Process.hs

@@ -518,7 +518,7 @@ cleanupNormal (_, _, _, procHandle) = do
 -- still hanging around.
 cleanupException ::
     (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) -> IO ()
-cleanupException (Just stdinH, Just stdoutH, stderrMaybe, ph) = do
+cleanupException (stdinMaybe, stdoutMaybe, stderrMaybe, ph) = do
     -- Send a SIGTERM to the process
 #ifdef USE_NATIVE
     terminate ph
@@ -529,8 +529,8 @@ cleanupException (Just stdinH, Just stdoutH, stderrMaybe, ph) = do
     -- Ideally we should be closing the handle without flushing the buffers so
     -- that we cannot get a SIGPIPE. But there seems to be no way to do that as
     -- of now so we just ignore the SIGPIPE.
-    hClose stdinH `catch` eatSIGPIPE
-    hClose stdoutH
+    whenJust (\stdinH -> hClose stdinH `catch` eatSIGPIPE) stdinMaybe
+    whenJust hClose stdoutMaybe
     whenJust hClose stderrMaybe
 
     -- Non-blocking wait for the process to go away
@@ -553,7 +553,6 @@ cleanupException (Just stdinH, Just stdoutH, stderrMaybe, ph) = do
             _ -> False
 
     eatSIGPIPE e = unless (isSIGPIPE e) $ throwIO e
-cleanupException _ = error "cleanupProcess: Not reachable"
 
 -- | Creates a system process from an executable path and arguments. For the
 -- default attributes used to create the process see 'mkConfig'.
@@ -873,8 +872,7 @@ toChunksWith modifier path args =
 
     where
 
-    run (_, Just stdoutH, _, _) = toChunksClose stdoutH
-    run _ = error "toChunksWith: Not reachable"
+    run (_, stdoutMaybe, _, _) = maybe Stream.nil toChunksClose stdoutMaybe
 
 -- | @toBytesEither path args@ runs the executable at @path@ using @args@ as
 -- arguments and returns the output of the process as a stream of 'Either'