lib: avoid realloc with zero size.

I spotted in the N3096 draft of ISO C (April 2023) that
a zero size in realloc is no longer defined behavior,
like it used to be. I don't know exactly when it changed;
in C99 it is not mentioned. We call realloc only in
one place, so we can defend agains this.

* lib.c (chk_realloc): If the new size is zero, we
implement the C99 and older semantics: deallocate the
object, and then behave like malloc(0). In other
cases, we use realloc.

0 files changed, 0 insertions, 0 deletions