gzip decompression stops early without error #37
Description
Originally raised against pipes-zlib as k0001/pipes-zlib#16, but the following program displays the same fault without pipes being involved:
#!/usr/bin/env stack
{- stack
--resolver lts-7.23
runghc
--package streaming-commons
--package turtle
-}
{-# LANGUAGE OverloadedStrings #-}
import qualified Codec.Compression.GZip as GZip
import Control.Exception (throwIO)
import qualified Data.ByteString.Lazy as L
import Control.Monad (foldM)
import Data.Streaming.Zlib
import Data.Text (unpack)
import Turtle
decompress :: L.ByteString -> IO L.ByteString
decompress gzipped = do
inf <- initInflate $ WindowBits 31
ungzipped <- foldM (go' inf) id $ L.toChunks gzipped
final <- finishInflate inf
return $ L.fromChunks $ ungzipped [final]
where
go' inf front bs = feedInflate inf bs >>= go front
go front x = do
y <- x
case y of
PRDone -> return front
PRNext z -> go (front . (:) z) x
PRError e -> throwIO e
main = do
fn <- options "GZip decompression test script" (argPath "file" "file to decompress")
-- lazy IO solution, works!
-- fmap GZip.decompress (L.readFile . unpack . format fp $ fn) >>= L.putStr
-- Streaming solution, stops early without error!
gzipped <- L.readFile . unpack . format fp $ fn
decompress gzipped >>= L.putStr... where my decompress is based on decompressRaw, and the test input file that reproduces the problem is, per the original issue, available here.