### Please describe the problem.

French messages in the `aria2c` client called from `git-annex` are garbled, probably double utf-8 encoded.

### What steps will reproduce the problem?

download a bittorrent url with git-torrent using a UTF8 locale.

### What version of git-annex are you using? On what operating system?

`5.20150205-gbf9058a` on current debian jessie.

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log

anarcat@marcos:iso(master)$ /srv/downloads.kitenet.net/git-annex/linux/current/git-annex.linux/git-annex addurl http://images.kali.org/kali-linux-1.1.0-amd64-mini.torrent
(downloading torrent file...)
--2015-02-09 22:08:58--  http://images.kali.org/kali-linux-1.1.0-amd64-mini.torrent
Résolution de images.kali.org (images.kali.org)… 50.7.37.130
Connexion à images.kali.org (images.kali.org)|50.7.37.130|:80… connecté.
requête HTTP transmise, en attente de la réponse… 200 OK
Taille : 2668 (2,6K) [application/octet-stream]
Sauvegarde en : « ../.git/annex/misctmp/torrent31107 »

100%[=====================================================================================================================================================================================================>] 2 668       --.-K/s   ds 0,002s

2015-02-09 22:08:59 (1,56 MB/s) — « ../.git/annex/misctmp/torrent31107 » sauvegardé [2668/2668]

addurl images.kali.org_kali_linux_1.1.0_amd64_mini.torrent/kali_linux_1.1.0_amd64_mini.iso (from bittorrent)


02/09 22:08:59 [ERROR] Exception caught while loading DHT routing table from /home/anarcat/.aria2/dht.dat
Exception: [DHTRoutingTableDeserializer.cc:83] errorCode=1 Failed to load DHT routing table from /home/anarcat/.aria2/dht.dat

02/09 22:08:59 [NOTICE] IPv4 DHT: listening on UDP port 6912

02/09 22:08:59 [ERROR] Erreur d'intégrité détectée. fichier=../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini

02/09 22:08:59 [NOTICE] IPv4 BitTorrent: listening on TCP port 6910

02/09 22:08:59 [NOTICE] IPv6 BitTorrent: listening on TCP port 6910
[#9acd0a 0B/27MiB(0%) CN:0 SD:0 DL:0B]
[#9acd0a 0B/27MiB(0%) CN:29 SD:0 DL:0B]
[#9acd0a 0B/27MiB(0%) CN:29 SD:1 DL:0B]
[#9acd0a 0B/27MiB(0%) CN:27 SD:5 DL:0B]
[#9acd0a 464KiB/27MiB(1%) CN:27 SD:6 DL:612KiB ETA:44s]
[#9acd0a 1.0MiB/27MiB(3%) CN:27 SD:6 DL:604KiB ETA:44s]
[#9acd0a 1.5MiB/27MiB(5%) CN:27 SD:7 DL:583KiB ETA:44s]
[#9acd0a 2.2MiB/27MiB(8%) CN:26 SD:8 DL:600KiB ETA:42s]
[#9acd0a 2.7MiB/27MiB(10%) CN:26 SD:10 DL:596KiB ETA:41s]
[#9acd0a 3.2MiB/27MiB(12%) CN:26 SD:11 DL:579KiB ETA:41s]
[#9acd0a 3.8MiB/27MiB(14%) CN:27 SD:11 DL:584KiB ETA:40s]
[#9acd0a 4.4MiB/27MiB(16%) CN:27 SD:11 DL:584KiB ETA:39s]
[#9acd0a 5.0MiB/27MiB(18%) CN:26 SD:11 DL:589KiB ETA:38s]
[#9acd0a 5.5MiB/27MiB(20%) CN:26 SD:11 DL:590KiB ETA:37s]
[#9acd0a 6.2MiB/27MiB(23%) CN:26 SD:11 DL:595KiB ETA:35s]
[#9acd0a 6.8MiB/27MiB(25%) CN:26 SD:11 DL:596KiB ETA:34s]
[#9acd0a 7.3MiB/27MiB(27%) CN:24 SD:9 DL:594KiB ETA:33s]
[#9acd0a 7.9MiB/27MiB(29%) CN:24 SD:9 DL:594KiB ETA:32s]
[#9acd0a 8.4MiB/27MiB(31%) CN:24 SD:10 DL:591KiB ETA:32s]
[#9acd0a 9.1MiB/27MiB(33%) CN:24 SD:10 DL:595KiB ETA:30s]
[#9acd0a 9.7MiB/27MiB(35%) CN:24 SD:10 DL:596KiB ETA:29s]
[#9acd0a 10MiB/27MiB(37%) CN:22 SD:9 DL:589KiB ETA:29s]
[#9acd0a 10MiB/27MiB(39%) CN:10 SD:8 DL:588KiB ETA:28s]
[#9acd0a 11MiB/27MiB(41%) CN:9 SD:8 DL:583KiB ETA:27s]
[#9acd0a 11MiB/27MiB(43%) CN:9 SD:8 DL:587KiB ETA:26s]
[#9acd0a 12MiB/27MiB(45%) CN:8 SD:7 DL:586KiB ETA:25s]
[#9acd0a 12MiB/27MiB(48%) CN:8 SD:7 DL:584KiB ETA:24s]
[#9acd0a 13MiB/27MiB(50%) CN:8 SD:8 DL:585KiB ETA:23s]
[#9acd0a 14MiB/27MiB(52%) CN:8 SD:8 DL:574KiB ETA:23s]
[#9acd0a 14MiB/27MiB(53%) CN:8 SD:8 DL:567KiB ETA:22s]
[#9acd0a 14MiB/27MiB(55%) CN:8 SD:8 DL:556KiB ETA:22s]
[#9acd0a 15MiB/27MiB(57%) CN:8 SD:8 DL:555KiB ETA:21s]
[#9acd0a 15MiB/27MiB(59%) CN:8 SD:8 DL:550KiB ETA:20s]
[#9acd0a 16MiB/27MiB(60%) CN:8 SD:8 DL:543KiB ETA:19s]
[#9acd0a 16MiB/27MiB(62%) CN:8 SD:8 DL:540KiB ETA:18s]
[#9acd0a 17MiB/27MiB(64%) CN:8 SD:8 DL:537KiB ETA:18s]
[#9acd0a 18MiB/27MiB(66%) CN:8 SD:8 DL:535KiB ETA:17s]
[#9acd0a 18MiB/27MiB(68%) CN:8 SD:8 DL:525KiB ETA:16s]
[#9acd0a 18MiB/27MiB(70%) CN:8 SD:8 DL:522KiB ETA:15s]
[#9acd0a 19MiB/27MiB(72%) CN:8 SD:8 DL:522KiB ETA:14s]
[#9acd0a 19MiB/27MiB(74%) CN:8 SD:8 DL:523KiB ETA:13s]
[#9acd0a 20MiB/27MiB(76%) CN:8 SD:8 DL:517KiB ETA:12s]
[#9acd0a 21MiB/27MiB(78%) CN:8 SD:8 DL:522KiB ETA:11s]
[#9acd0a 21MiB/27MiB(80%) CN:13 SD:8 DL:532KiB ETA:10s]
[#9acd0a 22MiB/27MiB(82%) CN:13 SD:8 DL:541KiB ETA:8s]
[#9acd0a 22MiB/27MiB(84%) CN:13 SD:8 DL:544KiB ETA:7s]
[#9acd0a 23MiB/27MiB(86%) CN:13 SD:8 DL:552KiB ETA:6s]
[#9acd0a 23MiB/27MiB(88%) CN:13 SD:8 DL:549KiB ETA:5s]
[#9acd0a 24MiB/27MiB(91%) CN:13 SD:8 DL:558KiB ETA:4s]
[#9acd0a 25MiB/27MiB(93%) CN:13 SD:8 DL:570KiB ETA:3s]
[#9acd0a 25MiB/27MiB(95%) CN:13 SD:8 DL:576KiB ETA:2s]
[#9acd0a 26MiB/27MiB(97%) CN:13 SD:8 DL:587KiB ETA:1s]
[#9acd0a 26MiB/27MiB(99%) CN:13 SD:8 DL:592KiB]

02/09 22:09:53 [NOTICE] Le téléchargement des fichiers sélectionnés est terminé.

02/09 22:09:53 [NOTICE] Le partage (seeding) est terminé
[#9acd0a SEED(0.0) CN:9 SD:4]
[#9acd0a SEED(0.0) CN:0 SD:0]

02/09 22:09:55 [NOTICE] Téléchargement terminé: ../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini

02/09 22:09:55 [NOTICE] Votre ratio de partage était de 0.0, envoyé/téléchargé=0B/27MiB


Résultats du téléchargement:
gid   |stat|avg speed  |path/URI
======+====+===========+=======================================================
9acd0a|OK  |   518KiB/s|../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini/kali-linux-1.1.0-amd64-mini.iso

Légende du statut:
(OK): téléchargement terminé.
ok
addurl images.kali.org_kali_linux_1.1.0_amd64_mini.torrent/kali_linux_1.1.0_amd64_mini.txt.sha1sum (from bittorrent)


02/09 22:09:56 [NOTICE] IPv4 DHT: listening on UDP port 6990

02/09 22:09:56 [NOTICE] Le fichier de contrôle défectueux ../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini.aria2 a été supprimé car le fichier téléchargé ../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini n'existe pas.

02/09 22:09:56 [ERROR] Erreur d'intégrité détectée. fichier=../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini

02/09 22:09:56 [NOTICE] IPv4 BitTorrent: listening on TCP port 6899

02/09 22:09:56 [NOTICE] IPv6 BitTorrent: listening on TCP port 6899
[#5f49f7 0B/75B(0%) CN:0 SD:0 DL:0B]
[#5f49f7 0B/75B(0%) CN:28 SD:0 DL:0B]
[#5f49f7 0B/75B(0%) CN:28 SD:1 DL:0B]

02/09 22:10:00 [NOTICE] Le téléchargement des fichiers sélectionnés est terminé.

02/09 22:10:00 [NOTICE] Le partage (seeding) est terminé
[#5f49f7 SEED(0.0) CN:22 SD:3]
[#5f49f7 SEED(0.0) CN:0 SD:0]

02/09 22:10:02 [NOTICE] Téléchargement terminé: ../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini

02/09 22:10:02 [NOTICE] Votre ratio de partage était de 0.0, envoyé/téléchargé=0B/75B


Résultats du téléchargement:
gid   |stat|avg speed  |path/URI
======+====+===========+=======================================================
5f49f7|OK  |      19B/s|../.git/annex/misctmp/URL--http&c%%images.kali.org%kali-linux-1.1.0-amd64-mini.torrent/kali-linux-1.1.0-amd64-mini/kali-linux-1.1.0-amd64-mini.txt.sha1sum

Légende du statut:
(OK): téléchargement terminé.
ok
(recording state in git...)
anarcat@marcos:iso(master +)$ locale
LANG=fr_CA.UTF-8
LANGUAGE=
LC_CTYPE="fr_CA.UTF-8"
LC_NUMERIC="fr_CA.UTF-8"
LC_TIME="fr_CA.UTF-8"
LC_COLLATE="fr_CA.UTF-8"
LC_MONETARY="fr_CA.UTF-8"
LC_MESSAGES="fr_CA.UTF-8"
LC_PAPER="fr_CA.UTF-8"
LC_NAME="fr_CA.UTF-8"
LC_ADDRESS="fr_CA.UTF-8"
LC_TELEPHONE="fr_CA.UTF-8"
LC_MEASUREMENT="fr_CA.UTF-8"
LC_IDENTIFICATION="fr_CA.UTF-8"
LC_ALL=
# End of transcript or log.
"""]]

Previous similar UTF-8 bug: [[forget_corrupts_non-ascii_chars]]. Looks similar. --[[anarcat]]