Comment by kazinator

ISO C allows:

  free(NULL); // convenient no-op, does nothing

  fflush(NULL); // flush all streams; done implicitly on normal exit

  time(NULL); // don't store time_t into a location, just return it

  strtol(text, NULL, 10);  // not interested in pointer to first garbage char

  setbuf(stream, NULL);  // allocate a buffer for stream

  realloc(NULL, size); // behave like malloc(size)

and others. More examples in POSIX and other APIs:

  sigprocmask(SIG_UNBLOCK, these_sigs, NULL); // not interested in previous signal mask

  CreateEventA(NULL, FALSE, FALSE, NULL); // no security attributes, no name

Reality just ran over your opinion, oops!