[nuxi7]

For the curious, the need to change the malloc behavior is not hypothetical:

https://sourceware.org/bugzilla/show_bug.cgi?id=6527

Basically for many years now glibc has been knowingly doing the wrong thing just to keep malloc_set_state/malloc_get_state working. Which as far as anyone knows, is used only by emacs. Keeping this interface alive for the sole benefit of an emacs optimization when it is blocking the fixes for fairly serious bugs is a pretty big bar to meet for justification.

In the end this is largely a non-issue as an Emacs developer noted that their configure script probes for the special glibc malloc API and if it doesn't exist then emacs will use its own malloc implementation. The conclusion is that once the glibc devs get their changes up, everyone can meet up again to make sure existing emacs binaries still run and that the API detection in the emacs configure script works right.

So props to Paul Eggert for being the only sane man in the room and pointing out that the drama was all for nothing.