Revert "disable buffering earlier"

This reverts commit 632137836b39462883483a621f9dd696ce1d73cc.

Still failing :( Seems that disabling buffering is not the solution.

3 files changed, 8 insertions, 12 deletions

diff --git a/src/Propellor/CmdLine.hs b/src/Propellor/CmdLine.hs
index 70bb0bf8..a36ec7f5 100644
--- a/src/Propellor/CmdLine.hs
+++ b/src/Propellor/CmdLine.hs
@@ -111,7 +111,6 @@ data CanRebuild = CanRebuild | NoRebuild
 defaultMain :: [Host] -> IO ()
 defaultMain hostlist = withConcurrentOutput $ do
 	useFileSystemEncoding
-	updatePrepare
 	Shim.cleanEnv
 	checkDebugMode
 	cmdline <- processCmdLine
diff --git a/src/Propellor/Protocol.hs b/src/Propellor/Protocol.hs
index bc8d9327..ae7e0404 100644
--- a/src/Propellor/Protocol.hs
+++ b/src/Propellor/Protocol.hs
@@ -53,7 +53,11 @@ sendMarked' h marker s = do
 	hFlush h
 
 getMarked :: Handle -> Marker -> IO (Maybe String)
-getMarked h marker = go =<< catchMaybeIO (hGetLine h)
+getMarked h marker = do
+	-- Avoid buffering anything in Handle, so that the data after
+	-- the marker will be available to be read from the underlying Fd.
+	hSetBuffering stdin NoBuffering
+	go =<< catchMaybeIO (hGetLine h)
   where
 	go Nothing = return Nothing
 	go (Just l) = case fromMarked marker l of
diff --git a/src/Propellor/Spin.hs b/src/Propellor/Spin.hs
index 732ec9b7..7146ad4c 100644
--- a/src/Propellor/Spin.hs
+++ b/src/Propellor/Spin.hs
@@ -5,7 +5,6 @@ module Propellor.Spin (
 	spin,
 	spin',
 	update,
-	updatePrepare,
 	gitPushHelper,
 	mergeSpin,
 ) where
@@ -350,20 +349,14 @@ findLastNonSpinCommit = do
 spinCommitMessage :: String
 spinCommitMessage = "propellor spin"
 
--- Avoid buffering anything read from stdin, so that
--- when gitPullFromUpdateServer runs git fetch, it sees all the data
--- it expects to.
---
--- Should be called very early in propellor start, before anything reads
--- from stdin.
-updatePrepare :: IO ()
-updatePrepare = hSetBuffering stdin NoBuffering
-
 -- Stdin and stdout are connected to the updateServer over ssh.
 -- Request that it run git upload-pack, and connect that up to a git fetch
 -- to receive the data.
 gitPullFromUpdateServer :: IO ()
 gitPullFromUpdateServer = reqMarked NeedGitPush gitPushMarker $ \_ -> do
+	-- Note that this relies on data not being buffered in the stdin
+	-- Handle, since such buffered data would not be available in the
+	-- FD passed to git fetch. 
 	hin <- dup stdInput
 	hout <- dup stdOutput
 	hClose stdin