pwd does not update when path component is renamed

[Krzysztof Żelechowski]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc -I/usr/src/packages/BUILD/bash-4.1 
-L/usr/src/packages/BUILD/bash-4.1/../readline-6.1
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-suse-linux-gnu' 
-DCONF_VENDOR='suse' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -fmessage-length=0 -O2 -Wall 
-D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables 
-fasynchronous-unwind-tables -g  -D_GNU_SOURCE -DRECYCLES_PIDS -Wall -g 
-std=gnu89 -Wuninitialized -Wextra -Wno-unprototyped-calls -Wno-switch-enum 
-Wno-unused-variable -Wno-unused-parameter -ftree-loop-linear -pipe 
-fprofile-use
uname output: Linux ne-1 2.6.34.7-0.2-desktop #1 SMP PREEMPT 2010-09-14 
14:21:06 +0200 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-suse-linux-gnu

Bash Version: 4.1
Patch Level: 7
Release Status: release

Description:
        The text of pwd and the value of $PWD return a cached value, regardless 
of the actual current path.

Repeat-By:
        mkdir '-p' 'a' && cd 'a' && mv '../a' '../b' && enable '-n' 'pwd' && 
builtin 'pwd' && pwd

Fix:
        cd '-P' '.'