err = argz_append (envz, envz_len, envz2, new_len);
err = __argz_append (envz, envz_len, envz2, new_len);
envz_merge (char **envz, size_t *envz_len, const char *envz2,	    size_t envz2_len, int override){  error_t err = 0;  while (envz2_len && ! err)    {      char *old = envz_entry (*envz, *envz_len, envz2);      size_t new_len = strlen (envz2) + 1;      if (! old)	err = argz_append (envz, envz_len, envz2, new_len);      else if (override)	{	  argz_delete (envz, envz_len, old);	  err = argz_append (envz, envz_len, envz2, new_len);	}      envz2 += new_len;      envz2_len -= new_len;    }  return err;}