Binary package hint: mc
Until recently I have been building mc with dpkg-buildpackage, and what I immediately noticed is that Ctrl+Enter was working as expected. Since I moved to 4.6.2 at the time I thought this must be something fixed in mc. Now I started using pbuilder and after I rebuilt the very same package Ctrl+Enter suddenly stopped working. Interestingly, both old and new .debs don't depend on any x11 libraries, yet behave differently.
I tried modifying Build-Dep by adding xorg-dev, and it surely helped in that Ctrl+Enter started working. xorg-dev is an overkill in this case, what needed is to find the exact library Midnight Commander depends on for this sort of functionality. Unfortunately I'm not familiar with x11 development at the moment, so I don't even know what it might be.
Please find what exactly Midnight Commander depends on for extra keyboard functionality and add it to Build-Dep. As far as I can see it is linked to it statically (whatever it is) and does not harm console mode in any way (even executable size doesn't change).
Just in case: I narrowed it down to just libx11-dev. Looking at the mc source I found that mc connects to x11 only when it can (and stops doing that if it's not available, or even if there are no x11 libraries out there). I think it must be safe to build it with this flag, and mc should still be usable on the server too.