Build fails on non-Windows OS

I do not have permission to re-open #4896 so I created this duplicate ticket.

This code in r3445:

  <basename file="@{file}" property="target" />

does not work. The ''immutable'' target property is not updated on the second and subsequent iterations of the loop.

To see what I mean take a look at build/dist/jquery-ui-1.8pre/ui/minified/jquery.effects.blind.min.js after performing a build.

Confirmed in Ubuntu 9.10 using Ant 1.7.1.

I've (hopefully) attached a patch to fix this problem.