DIRSTACK[0] contains literal "~"

[jeremy.richards]

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-redhat-linux-gnu' 
-DCONF_VENDOR='redhat' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -O2 -g -pipe -Wall 
-Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong 
--param=ssp-buffer-size=4 -grecord-gcc-switches   -m64 -mtune=generic
uname output: Linux Cyborg.localdomain 3.10.0-693.21.1.el7.x86_64 #1 SMP Wed 
Mar 7 19:03:37 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-redhat-linux-gnu

Bash Version: 4.2
Patch Level: 46
Release Status: release

Description:
    I noticed some strange behavior in the DIRSTACK variable (used in 
pushd/popd). 
    `declare -p DIRSTACK`
    shows the list of current directories on the stack, as expected. 
${DIRSTACK[@]:1} show correctly expanded paths, i.e., “pushd ~/Jenkins” 
will correctly store "/home/jeremy/jenkins"
    However, ${DIRSTACK[0]} does NOT have this behavior, and will encode a 
literal tilde, e.g., "~/jenkins"
    This behavior is obfuscated by 
    dirs -v 
    and
    dirs -l
    The first option will *always* display the stack with ~ instead of $HOME, 
and the second option will *always* display $HOME instead of ~.

    This means, for instance, that rearranging the order of the DIRSTACK array 
can produce invalid directory targets. 


Repeat-By:
    mkdir -p ~/some/test/path
    cd ~/some/test/path
    pushd ~/some/test/
    pushd ~/some/
    declare -p DIRSTACK
    #output will show literal ~ in ${DIRSTACK[0]}
    pushd +0 #works, but I believe this is because it just says "don't need to 
move"
    pushd +1 #works
    DIRSTACK[1]=${DIRSTACK[0]}
    pushd +1 #fails, "no such file or directory" because ~ isn't expanded

Fix:
    Don't store ~ in ${DIRSTACK[0]}. pushd ~/some/ will be correctly expanded, 
this just needs to be implemented for the current directory as well. I know you 
probably wanted a technical fix here, sorry.