ungzip truncates concatinated gz streams

[lpsmith]

Likely closely related to snapframework/io-streams#56

I recently learned that it's perfectly acceptable to concatinate gz streams, and gunzip and zcat will decompress each stream and concatinate the result. So starting with this minimal reimplementation of zcat:

import Data.Conduit (($$), ($=))
import Control.Monad.Trans.Resource(runResourceT)
import qualified Data.Conduit.Binary as CB
import Data.Conduit.Zlib
import System.IO
import System.Environment

main = do
    (filename:_) <- getArgs
    runResourceT $ CB.sourceFile filename $= ungzip $$ CB.sinkHandle stdout

Then, in the shell, here's a minimal demonstration of the problem:

$ echo Hello | gzip > foo.gz
$ echo World | gzip >> foo.gz
$ dist/build/zcat/zcat foo.gz
Hello
$ zcat foo.gz
Hello
World
$ gunzip foo.gz
$ cat foo
Hello
World

[lpsmith]

Ahh, my apologies for overlooking multiple. This probably isn't great UX, given the lack of correspondence between ungzip and gunzip.