Hi. This idea just came into my head: why not #ifdef'ing the deprecated code and having configure.ac option "--disable-backcompat"?
Examples: User A has an old config. So he downloads the new package, compiles it and installs it just like he allways did. User B has a new config and wants to compile fvwm so that it doesn't waste time/space looking for deprecated options. This could make fvwm run a tiny bit faster (?), and also would allow user B to see if its config is up-to-date (i.e., not using deprecated options). He downloads the new package, runs configure --disable-backcompat and compiles it. The performance gain may not be that noticeable, but it would allow us to mark clearly deprecated code and test if things work without it. Maybe it would make it easyer to remove in the future (?). It would also be useful for users who want to make sure they have an up-to-date config, being this a way to enforce that. What do you think? Renato