"cd //" isn't the same as "cd /" or "cd ///"

[Noah Spurrier]

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 -Wformat-security
-Werror=format-security -Wall
uname output: Linux se 3.2.0-26-generic #41-Ubuntu SMP Thu Jun 14
17:49:24 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 4.2
Patch Level: 24
Release Status: release

Description:

    Executing `cd //` will put you in the root directory as expected;
    however executing `pwd` will report "//" as your working directory.
    Also, if your Bash prompt has "$PWD" in it then it will also
    report "//" as your working directory. This quirk appears only
    with the Bash builtin version of `pwd`; the GNU Coreutil version of
    `/bin/pwd` will report "/" as expected.

    Also note that if you execute `cd ///` or `cd ////` or `cd /////`, etc...
    then you will be put in the root directory and `pwd` will report "/"
    as expected. In other words, this quirk appears only if you cd to "//".

Repeat-By:
    #!/bin/bash
    cd /
    pwd
    /usr/bin/pwd
    cd //
    pwd
    /usr/bin/pwd
    cd ///
    pwd
    /usr/bin/pwd
    cd ////
    pwd
    /usr/bin/pwd
    cd /////
    pwd
    /usr/bin/pwd