[pkg-lighttpd] Bug#521235: lighttpd: Adding modules to server.modules not idempotent

[Josh Triplett]

Package: lighttpd
Version: 1.4.19-5
Severity: normal

Adding a module to server.modules multiple times can cause it to fail.
I'd like to make my site configuration files self-contained, listing all
the modules they need.  Thus, I had two different site configuration
files containing the following:

server.modules += (
    "mod_fastcgi",
    "mod_redirect",
    "mod_rewrite",
)

Doing so caused a strange failure, where a fake path introduced in a
rewrite-once rule and used in a fastcgi rule ended up getting passed to
the fastcgi when it shouldn't.

In general, adding something to server.modules twice should have no
effect, and this should not depend on the workings of the individual
modules in question, only on the behavior of server.modules.

- Josh Triplett