Function if

system/lib/dlmalloc.c:5288–5290

    }
#ifdef REALLOC_ZERO_BYTES_FREES
    else if (bytes == 0) {
        dlfree(oldmem);
    }
#endif /* REALLOC_ZERO_BYTES_FREES */
    else {
        size_t nb = request2size(bytes);