* John Scott: > No system is known to set errno when using free, successfully or > otherwise, and POSIX Issue 8 is slated to protect it on success > to simplify error handling: > https://www.austingroupbugs.net/view.php?id=385
glibc currently does: <https://sourceware.org/bugzilla/show_bug.cgi?id=17924> We're going to fix it eventually, but current versions have this behavior for now.