I may be overdoing it a bit here, but personally I don't agree with Torvald's p.o.v. at all. While user experience is obviously important, allowing mistakes like this to go unchallenged by simply providing a work-around just encourages people to write broken software. Specs exist for a reason. Ignoring them is not it.
I do this in my own software as well. If a user files a bug because input X fails to process as expected -- and it turns out his/her input does not meet the spec -- I do not supply a fix. Even if his/her supplied input is widely used in 'the wild'. While this alienates a considerable user base, I refuse to be part of the problem.