404 Override Not Working

Wolfgang1983 assumed that setting the 404_override would effect the way show_404 is executed by CI. I have pointed out that this is not the case as the two are unrelated. Just take a look at CodeIgniter.php starting at line 447. Setting the 404_override only causes CI to load the custom 404 Controller instead of calling the show_404 method.

What if they only need one 404 page for their application?

Even if this is true, again, you are changing code to do something which can easily be done by creating a method specifically designed for the situation.

I like to think ahead when coding. So say, for now only one 404 page is needed. But in the future you do need one for the forum and one for any other part of the website. You would then need to undo the solution you have provided, and build a separate method as I have suggested. Or as you point out, do something based on the passed in page argument. But then you he would need to pass in the correct page argument to execute the correct 404.

I don't see how this is "fixing something that is not broken", it's changing how something works so it suits your specific needs.

Changing how something works indeed is not fixing something that is broken. But changing something based on a wrong interpretation of the Core code is not the correct approach.

PS. When I said custom Controller, I'm was talking about the custom 404 Controller