restart coprocess in raw mode

Restarting a crashing git process could result in filename encoding issues
when not in a unicode locale, as the restarted processes's handles were not
read in raw mode.

Since rawMode is always used when starting a coprocess, didn't bother
to parameterise it and just always enable it for simplicity.

This commit was sponsored by Jake Vosloo on Patreon.

CHANGELOG

@@ -1,3 +1,11 @@
+git-annex (6.20161032) UNRELEASED; urgency=medium
+
+  * Restarting a crashing git process could result in filename encoding
+    issues when not in a unicode locale, as the restarted processes's
+    handles were not read in raw mode.
+
+ -- Joey Hess <id@joeyh.name>  Tue, 01 Nov 2016 14:02:06 -0400
+
 git-annex (6.20161031) unstable; urgency=medium
 
   * Assistant, repair: Fix ignoring of git fsck errors due to

Git/CatFile.hs

@@ -51,7 +51,7 @@ catFileStart' restartable repo = CatFileHandle
 	<$> startp "--batch"
 	<*> startp "--batch-check=%(objectname) %(objecttype) %(objectsize)"
   where
-	startp p = CoProcess.rawMode =<< gitCoProcessStart restartable
+	startp p = gitCoProcessStart restartable
 		[ Param "cat-file"
 		, Param p
 		] repo

Git/CheckAttr.hs

@@ -24,7 +24,7 @@ type Attr = String
 checkAttrStart :: [Attr] -> Repo -> IO CheckAttrHandle
 checkAttrStart attrs repo = do
 	currdir <- getCurrentDirectory
-	h <- CoProcess.rawMode =<< gitCoProcessStart True params repo
+	h <- gitCoProcessStart True params repo
 	oldgit <- Git.Version.older "1.7.7"
 	return (h, attrs, oldgit, currdir)
   where

Git/CheckIgnore.hs

@@ -37,7 +37,7 @@ type CheckIgnoreHandle = CoProcess.CoProcessHandle
  -}
 checkIgnoreStart :: Repo -> IO (Maybe CheckIgnoreHandle)
 checkIgnoreStart repo = ifM supportedGitVersion
-	( Just <$> (CoProcess.rawMode =<< gitCoProcessStart True params repo')
+	( Just <$> gitCoProcessStart True params repo'
 	, return Nothing
 	)
   where

Git/HashObject.hs

@@ -20,7 +20,7 @@ import Utility.Tmp
 type HashObjectHandle = CoProcess.CoProcessHandle
 
 hashObjectStart :: Repo -> IO HashObjectHandle
-hashObjectStart = CoProcess.rawMode <=< gitCoProcessStart True
+hashObjectStart = gitCoProcessStart True
 	[ Param "hash-object"
 	, Param "-w"
 	, Param "--stdin-paths"

Git/Tree.hs

@@ -59,7 +59,7 @@ newtype MkTreeHandle = MkTreeHandle CoProcess.CoProcessHandle
 withMkTreeHandle :: (MonadIO m, MonadMask m) => Repo -> (MkTreeHandle -> m a) -> m a
 withMkTreeHandle repo a = bracketIO setup cleanup (a . MkTreeHandle)
   where
-	setup = CoProcess.rawMode =<< gitCoProcessStart False ps repo
+	setup = gitCoProcessStart False ps repo
 	ps = [Param "mktree", Param "--batch", Param "-z"]
 	cleanup = CoProcess.stop
 

Utility/CoProcess.hs

@@ -13,7 +13,6 @@ module Utility.CoProcess (
 	start,
 	stop,
 	query,
-	rawMode
 ) where
 
 import Common
@@ -44,7 +43,15 @@ start numrestarts cmd params environ = do
 start' :: CoProcessSpec -> IO CoProcessState
 start' s = do
 	(pid, from, to) <- startInteractiveProcess (coProcessCmd s) (coProcessParams s) (coProcessEnv s)
+	rawMode from
+	rawMode to
 	return $ CoProcessState pid to from s
+  where
+	rawMode h = do
+		fileEncoding h
+#ifdef mingw32_HOST_OS
+		hSetNewlineMode h noNewlineTranslation
+#endif
 
 stop :: CoProcessHandle -> IO ()
 stop ch = do
@@ -79,16 +86,3 @@ query ch send receive = do
 			{ coProcessNumRestarts = coProcessNumRestarts (coProcessSpec s) - 1 }
 		putMVar ch s'
 		query ch send receive
-
-rawMode :: CoProcessHandle -> IO CoProcessHandle
-rawMode ch = do
-	s <- readMVar ch
-	raw $ coProcessFrom s
-	raw $ coProcessTo s
-	return ch
-  where
-	raw h = do
-		fileEncoding h
-#ifdef mingw32_HOST_OS
-		hSetNewlineMode h noNewlineTranslation
-#endif