Associative array assignment crashes Bash interpreter

[ben]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include -I../bash/lib  
-D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat 
-Werror=format-security -Wall
uname output: Linux franklin 3.11.0-13-generic #20-Ubuntu SMP Wed Oct 23 
07:38:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 4.2
Patch Level: 45
Release Status: release

Description:
        The included scripts generate a "division by zero" and "recursion level 
exceeded" errors. Confirmed in
    Bash 4.2.45, 4.1.5, and 4.1.2.

Repeat-By:

-------------------------------------------------------------------------
#!/bin/bash

declare -A x
x[/etc/hadoop/conf/core-default.xml]=x

for n in n/core-default.xml
do
    f="/etc/hadoop/conf/`basename $n`"
    if [ -n "${x[$f]}" ]; then for m in ${foo[$n]}; do echo; done
    fi
done
-------------------------------------------------------------------------

-------------------------------------------------------------------------
#!/bin/bash

declare -A x
x[/etc/hadoop/conf/core-default.xml]=x

for n in on/core-default.xml
do
    f="/etc/hadoop/conf/`basename $n`"
    if [ -n "${x[$f]}" ]; then for m in ${foo[$n]}; do echo; done
    fi
done
-------------------------------------------------------------------------