\c escape within $'...' can produce mangled UTF-8

[Dmitry Groshev]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu'
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/local/share/locale'
-DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H   -I.  -I. -I./include
-I./lib   -g -O2
uname output: Linux wjlair 2.6.24.5-smp #1 SMP Fri Aug 14 19:13:09 MSD
2009 i686 AMD Athlon(tm) 64 X2 Dual Core Processor 5200+ AuthenticAMD
GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 4.1
Patch Level: 0
Release Status: release

Description:
        In UTF-8 locale (such as ru_RU.UTF-8), a \c escape within
$'...' results in an invalid UTF-8 string if followed by an UTF-8
character: ansicstr() in lib/sh/strtrans.c consumes and converts the
character's first byte, leaving the rest of UTF-8 sequence as it were.

Repeat-By:
        echo $'\cА' > utf8bug.txt

        The "А" character in the example is cyrillic - U+0410, UTF-8: 0xD0
0x90 . It gets transformed into 0x10 0x90 which is invalid UTF-8.

-- 
-= With best regards, Dmitry Groshev =-