jenkinsci/parameterized-trigger-plugin — pull request #20 by fredg02 (2012-05-06 22:01:01+00:00)
Title: [FIXED JENKINS-8916] Allowing same type of parameter for triggered build more than once seems redundant

It uses the new "oneEach" attribute of the "f:hetero-list" jelly tag. Jenkins core version 1.463 is required to make it work, but it's backwards compatible so no dependency on 1.463 is introduced.