Invalid bounds are ignored without raising a warning or an error

[tjstienstra]

While debugging one of my own problems. I finally found out one of the reasons it was invalid, namely my bound was just being ignored as it was not directly a normal parameter. I would prefer that instead an error is raised, which can easily be done by adding an else statement here.

[moorepants]

Seems like a good suggestion.

[moorepants]

This has been fixed at some point.