`builderToByteString` add an empty string when flushing.

[yi huang]

Is it intended or a bug?

{-# LANGUAGE OverloadedStrings #-}

import Data.ByteString.Char8 ()
import Data.Monoid (mappend)
import qualified Blaze.ByteString.Builder as B
import Data.Conduit.Blaze (builderToByteString)

import Data.Conduit
import qualified Data.Conduit.List as CL

main :: IO ()
main = do
    r <- CL.sourceList ["1", "2"]
           $$ CL.map B.fromByteString
           =$ CL.map (`mappend` B.flush)
           =$ builderToByteString
           =$ CL.consume
    print r 

-- output: ["1","","2",""]

[Michael Snoyman]

This looks buggy to me. I'll try to look at this in the next few days.

[yi huang]

I did some investigation to find that, `flush` is identical to `insertByteString S.empty`, we can make blaze-builder-conduit to ignore inserting of empty bytestring, that also prevents intentionally inserting of empty bytestring, it wouldn't cause any breakages i guess.

--
http://yi-programmer.com/

[Michael Snoyman]

I like it. Thanks for the pull request, it's merged and release as 0.4.0.2.