Secondary industries check for other secondary industries before building, to avoid the scenario where a map with only two cities of population 300 has two oil refineries but no factories, for example. Industry selection is handled just fine by vanilla OpenTTD code, so this will be cut.
Secondary industries check for other secondary industries before building, to avoid the scenario where a map with only two cities of population 300 has two oil refineries but no factories, for example. Industry selection is handled just fine by vanilla OpenTTD code, so this will be cut.