Bug#349010: debian-policy: Chapter 6 - Package maintainer scripts: redundant info about exit status

[Daniel Bonniot <bonniot@users.sf.net>]

Package: debian-policy
Severity: minor


Section 6.1, third paragraph, says that maintainer scripts, should exit 
with non-zero on error. Then section 6.3 (titled "Controlling terminal 
for maintainer scripts"), says: "Each script should return a zero exit 
status for success, or a nonzero one for failure."

First, I don't think this has anything to do with the controlling 
terminal. Second, this info should be regrouped in one place (not merely 
delete the second one, because the first one does not explicitely say it 
should be zero on success). Maybe the best would be to create a new 
section, just after the introduction. Proposal:


6.2 Exit status

The package management system looks at the exit status from these 
scripts. Each script must return a zero exit status for success, 
or a nonzero one for failure.

It is important that they exit with a non-zero status if there 
is an error, so that the package management system can stop its 
processing. For shell scripts this means that you almost always need to 
use set -e (this is usually true when writing shell scripts, in fact). 
It is also important, of course, that they don't exit with a non-zero 
status if everything went well.


Feel free to adjust. Note that I replaced the "should return..." by 
"must return..." as I think it is a requirement, but undo that if I am 
wrong, AINAPE (policy expert!).

Cheers,

Daniel

-- System Information:
Debian Release: testing/unstable
  APT prefers testing
  APT policy: (900, 'testing'), (99, 'unstable')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.12-1-686
Locale: LANG=en_US, LC_CTYPE=en_US (charmap=ISO-8859-1)