[Pkg-samba-maint] Bug#866258: samba-common-bin: maintainer script(s) not using strict mode

[treinen at debian.org]

Package: samba-common-bin
Version: 2:4.6.5+dfsg-2
Severity: normal
User: treinen at debian.org
Usertags: colis-shparser

Dear maintainer,

at least one of the maintainer scripts (preinst, postinst, prerm,
postrm) of the package samba-common-bin does not use strict mode.
Policy section 10.4 says:

"Shell scripts (sh and bash) [..] should almost certainly start with
set -e so that errors are detected."

"Every script should use set -e or check the exit status of every
command."

Please insert a "set -e" at the beginning of your script to enable
strict mode. You should not replace this by a first line "#!/bin/sh
-e" as it is not effective when your script is executed by an
explicit invocation of sh.

Note that this might make your script fail in cases where it did not
fail before. This is the purpose of strict mode - make it fail when
any unexpected error is encountered. You should make sure that you
catch any error (non-zero exit codes of commands) that you decide to
tolerate. Techniques to locally catch an error include using
appropriate options to your command when available, adding a " ||
true" at the end of the command, or selectively switching off strict
mode by "set +e" and switching it back on again later by "set -e". 

This bug filing has been discussed and approved in thread [1].

-Ralf.

[1] https://lists.debian.org/debian-devel/2017/06/msg00342.html