The postinst starts the index update in the background using the '&' shell operator. This seems sloppy to me, and it leaves things running after apt-get has exitted which causes problems for automated systems. Specifically this broke diskimage-builder (https://git.openstack.org/cgit/diskimage-builder) in really awful ways when apt-xapian-index was updated.
This is a violation of policy IMO, as the script should run invoke-rc.d. The use of policy-rc.d directly seems improper.
ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: apt-xapian-index 0.45ubuntu2
ProcVersionSignature: Ubuntu 3.8.0-30.44-generic 3.8.13.6
Uname: Linux 3.8.0-30-generic x86_64
ApportVersion: 2.9.2-0ubuntu8.3
Architecture: amd64
Date: Wed Sep 18 17:02:22 2013
InstallationDate: Installed on 2013-01-14 (247 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64+mac (20121017.3)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: apt-xapian-index
UpgradeStatus: Upgraded to raring on 2013-04-30 (141 days ago)
Subscribing ubuntu-security.
Just wanted to note that the recent security update caused us some grief due to this bug.