On Thu, Jun 19, 2025 at 01:42:38PM -0500, Eric Blake wrote: > > + > > + The glibc implementation of realloc() is not consistent with > > + that, and as a consequence, it is dangerous to call > > + realloc(p, 0) in glibc. > > More importantly, with C23 making it undefined behavior, it is > dangerous to call realloc(non_null, 0) in ANY libc, ever. Regardless > of whether glibc documents semantics that comply (or don't comply) > with older standards.
That is, unless a future revision of POSIX adds intentional <CX> shading to state that on POSIX platforms, realloc(non_null, 0) has well-defined behavior, and therefore making it usable on POSIX systems even if not appropriate for generic C systems. -- Eric Blake, Principal Software Engineer Red Hat, Inc. Virtualization: qemu.org | libguestfs.org
