bittorrent: Fix mojibake introduced in parsing arai2c progress output.

hGetSomeString reads one byte at a time, so unicode bytes are not composed.
The problem comes when outputting that to the console with hPut; that
tried to apply the handle's encoding, and so we get mojibake.

Instead, use ByteStrings, and only convert it to a string for parsing, not
for display.

Note that there are a couple of other things that use hGetSomeString,
which I've left as-is for now.

Utility/Metered.hs

@@ -1,6 +1,6 @@
 {- Metered IO
  -
- - Copyright 2012, 2013 Joey Hess <id@joeyh.name>
+ - Copyright 2012-2105 Joey Hess <id@joeyh.name>
  -
  - License: BSD-2-clause
  -}
@@ -17,6 +17,7 @@ import System.IO.Unsafe
 import Foreign.Storable (Storable(sizeOf))
 import System.Posix.Types
 import Data.Int
+import Data.Bits.Utils
 
 {- An action that can be run repeatedly, updating it on the bytes processed.
  -
@@ -163,12 +164,13 @@ commandMeter progressparser meterupdate cmd params = liftIO $ catchBoolIO $
 	p = proc cmd (toCommand params)
 
 	feedprogress prev buf h = do
-		s <- hGetSomeString h 80
+		b <- S.hGetSome h 80
-		if null s
+		if S.null b
 			then return True
 			else do
-				putStr s
+				S.hPut stdout b
 				hFlush stdout
+				let s = w82s (S.unpack b)
 				let (mbytes, buf') = progressparser (buf++s)
 				case mbytes of
 					Nothing -> feedprogress prev buf' h

debian/changelog

@@ -20,6 +20,7 @@ git-annex (5.20150206) UNRELEASED; urgency=medium
   * Improve race recovery code when committing to git-annex branch.
   * addurl: Avoid crash if quvi is not installed, when git-annex was
     built with process-1.2
+  * bittorrent: Fix mojibake introduced in parsing arai2c progress output.
 
  -- Joey Hess <id@joeyh.name>  Fri, 06 Feb 2015 13:57:08 -0400
 

doc/bugs/aria2c_display_broken_in_git-annex/comment_1_770e1d657bba2a3f5782eac2e8bdca57._comment

@@ -0,0 +1,14 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 1"""
+ date="2015-02-10T16:11:09Z"
+ content="""
+This is because aria2c detects it's not outputting to a terminal, so it
+stops using \r for progress displays. You can get the same effect by piping
+aria2c to less. There does not seem to be any switch to force console-style
+output.
+
+The only solution would be the complexity of making git-annex use a pty
+internally, or just not showing aria2c progress output (or not intercepting
+it for metering).
+"""]]

doc/bugs/bittorrent_special_url_double-encoding.mdwn

@@ -173,3 +173,5 @@ LC_ALL=
 """]]
 
 Previous similar UTF-8 bug: [[forget_corrupts_non-ascii_chars]]. Looks similar. --[[anarcat]]
+
+> [[fixed|done]] --[[Joey]]