Merge pull request #11490 from tobymao/1837-minor-share-on-merge

[1837] Remove minor shares on merge and UG train limit

lib/engine/game/g_1837/game.rb

@@ -523,7 +523,7 @@ def merge_minor!(minor, corporation, allow_president_change: true)
             @log << "#{corporation.name} receives token (#{new_token.used ? new_token.city.hex.id : 'charter'})"
           end
 
-          close_minor!(minor)
+          coal_company_exchange ? close_minor!(minor) : close_corporation(minor, quiet: true)
           graph.clear_graph_for(corporation)
         end
 
@@ -693,6 +693,12 @@ def remove_reservations!(entity, coordinates)
           coordinates.each { |coord| hex_by_id(coord).tile.remove_reservation!(entity) }
         end
 
+        def train_limit(entity)
+          return 2 if ug_minors.include?(entity)
+
+          super
+        end
+
         def must_buy_train?(entity)
           %i[major national].include?(entity.type) && super
         end