Changing the slug generated for fURL ?

[SuN T4A]

Hi everyone !

I'm currently trying out IPS4 RC6 in order to know if I will switch my 3.4.x board to it, and how it will go if I do it. One of my main area of concern is friendly URLs. My current board is pretty old, with many URLs that need to stay the way they are so that we don't lose too much SEO and don't need to do too many 301s.

So I've been playing a bit with the friendly URLs settings to see if I can get the same structure as before, and it works pretty well. The only thing that bothers me is that on IPS4 the slug generated for my URLs contains accented character instead of the non-accented equivalent I have currently in my URL, and since my board is in french it happens a lot. So for example a topic titled "Présentation" on my 3.4 board has forum/presentation-t125 as a URL, but after doing the upgrade (on a test forum, not on the live one) I have forum/présentation-t125

Is there any way to change how slugs are generated so that I can go back to the old non-accented one? I haven't found any settings about that, but maybe I missed it. Or do I have to change the source code directly? If so, where is it located?

Thank you very much if you can help me with that.