popd with garbage parameter removes entry from dirs but doesn't cd.

[gazelle]

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../. -I.././include -I.././lib  -D_FORTIFY_SOURCE=2 -g 
-O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat 
-Werror=format-security -Wall
uname output: Linux shell 3.13.0-111-generic #158-Ubuntu SMP Wed Feb 22 
16:12:03 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 4.3
Patch Level: 11
Release Status: release

Description:
        popd with garbage parameter removes entry from dirs but doesn't cd.
        Example: popd lsdfjlskfj

Repeat-By:
        cd /some/directory
        pushd /tmp
        dirs
        popd skdfhksjdfhkjsdf
        pwd;dirs

Fix:
        I assume it should generate an error message for the garbage parameter
        and not change the contents of the directory stack.