Package: busybox Version: 1:1.22.0-19+b2 Severity: normal Usertags: home The HOME environment variable does not have to be present, programs must fall back to the value in the passwd file. busybox sh does not do this in the following two places. * When running cd without any argument * When expanding tilde (~) characters Interestingly, the prompt does work even if HOME is unset. The busybox documentation doesn't specify any behaviour for these. POSIX leaves both of these as implementation defined so it would be good if busybox sh falls back on the user's home dir if HOME is unset. http://pubs.opengroup.org/onlinepubs/9699919799/utilities/cd.html http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_01 pabs@chianamo ~ $ busybox sh BusyBox v1.22.1 (Debian 1:1.22.0-19+b2) built-in shell (ash) Enter 'help' for a list of built-in commands. ~ $ echo ~ /home/pabs ~ $ unset HOME ~ $ echo ~ ~ ~ $ exit pabs@chianamo ~ $ busybox sh BusyBox v1.22.1 (Debian 1:1.22.0-19+b2) built-in shell (ash) Enter 'help' for a list of built-in commands. ~ $ pwd /home/pabs ~ $ mkdir tmp ~ $ cd tmp ~/tmp $ pwd /home/pabs/tmp ~/tmp $ cd ~ $ pwd /home/pabs ~ $ unset HOME ~ $ pwd /home/pabs ~ $ cd tmp ~/tmp $ pwd /home/pabs/tmp ~/tmp $ cd ~/tmp $ pwd /home/pabs/tmp -- System Information: Debian Release: 9.0 APT prefers testing-debug APT policy: (900, 'testing-debug'), (900, 'testing'), (860, 'testing-proposed-updates'), (800, 'unstable-debug'), (800, 'unstable'), (790, 'buildd-unstable'), (700, 'experimental-debug'), (700, 'experimental'), (690, 'buildd-experimental') Architecture: amd64 (x86_64) Kernel: Linux 4.9.0-2-amd64 (SMP w/4 CPU cores) Locale: LANG=en_AU.utf8, LC_CTYPE=en_AU.utf8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages busybox depends on: ii libc6 2.24-9 busybox recommends no packages. busybox suggests no packages. -- no debconf information -- bye, pabs https://wiki.debian.org/PaulWise
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