permalink / redirect problem

Hi,

it looks like wordpress acts kinda strange when using post_id in permalinks.

Let’s say the permalink format is /%postname%-%post_id% and the sample post name ist “test” with the post id 3556. The default slug generated by wordpress would be “/test-3556” which basically is great but… when surfing to “/a-completely-different-post-url-3556” i get the content of post 3556 without getting redirected to the correct slug.

Is this intentional? This is kind of a dangerous “feature” as any enemy of a blog using this structure could link posts this “strange” way to fire masses of duplicate content into the google index which would most probably lead to penalties by google or at least make any SEO effort useless.

Is there probably any workaround for that yet? Does anyone know a plugin that redirects that cases?

Thanks for helping