Infinite loop on clearing PWD

[jengelh]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc -I/usr/src/packages/BUILD/bash-3.2 
-L/usr/src/packages/BUILD/bash-3.2/../readline-5.2
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 -Wextra -Wno-unprototyped-calls -Wno-switch-enum -pipe -fPIE 
-fprofile-use
uname output: Linux borg 2.6.31.3-jen90-default #1 SMP 2009-10-06 00:27:29 
+0200 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-suse-linux-gnu

Bash Version: 3.2
Patch Level: 39
Release Status: release

Description:
        bash enters into an infinite loop when the environment variable PWD
        is unset. Probably not a smart thing to do, but since this variable
        is so important, it should probably be ensured that it does not get
        an empty value. (It does handle non-absolute paths in some random
        fashion, too.)

Repeat-By:
        $ unset PWD