avoid DISCONNECTED_ROUTE false negatives (TravelMapping#610)

rebase 49288bc
itself a rebase of c627aec

siteupdate/cplusplus/classes/HighwaySystem/route_integrity.cpp

@@ -12,8 +12,8 @@ void HighwaySystem::route_integrity(ErrorList& el)
 	{	// check for unconnected chopped routes
 		if (!r.con_route)
 			el.add_error(systemname + ".csv: root " + r.root + " not matched by any connected route root.");
-
 		// per-route CSV datachecks
+		else	r.con_mismatch();
 		#define CSV_LINE r.system->systemname + ".csv#L" + std::to_string(r.index()+2)
 		if (r.abbrev.empty())
 		{	if ( r.banner.size() && !strncmp(r.banner.data(), r.city.data(), r.banner.size()) )
@@ -78,33 +78,35 @@ void HighwaySystem::route_integrity(ErrorList& el)
 	}
 
 	for (ConnectedRoute& cr : con_routes)
-	{	if (cr.roots.empty()) continue; // because there could be an invalid _con.csv entry
-		// check cr.roots[0] by itself outside of loop
-		cr.roots[0]->con_mismatch();
-		for (size_t i = 1; i < cr.roots.size(); i++)
-		{	// check for mismatched route endpoints within connected routes
-			auto& q = cr.roots[i-1];
-			auto& r = cr.roots[i];
-			r->con_mismatch();
-			if ( q->points.size > 1 && r->points.size > 1 && !r->con_beg()->same_coords(q->con_end()) )
-			{	if	( q->con_beg()->same_coords(r->con_beg()) )
-					q->set_reversed();
-				else if ( q->con_end()->same_coords(r->con_end()) )
-					r->set_reversed();
-				else if ( q->con_beg()->same_coords(r->con_end()) )
-				{	q->set_reversed();
-					r->set_reversed();
-				}
-				else
-				{	Datacheck::add(r, r->con_beg()->label, "", "",
-						       "DISCONNECTED_ROUTE", q->con_end()->root_at_label());
-					Datacheck::add(q, q->con_end()->label, "", "",
-						       "DISCONNECTED_ROUTE", r->con_beg()->root_at_label());
-					cr.disconnected = 1;
-					q->set_disconnected();
-					r->set_disconnected();
-				}
-			}
-		}
-	}
+	  for (size_t i = 1; i < cr.roots.size(); i++)
+	  {	// check for mismatched route endpoints within connected routes
+		auto& q = cr.roots[i-1];
+		auto& r = cr.roots[i];
+		auto flag = [&]()
+		{	Datacheck::add(q, q->con_end()->label, "", "", "DISCONNECTED_ROUTE",  r->points[0].root_at_label());
+			Datacheck::add(r,  r->points[0].label, "", "", "DISCONNECTED_ROUTE", q->con_end()->root_at_label());
+			cr.disconnected = 1;
+			q->set_disconnected();
+			r->set_disconnected();
+		};
+		if ( q->points.size > 1 && r->points.size > 1 && !r->points.begin()->same_coords(q->con_end()) )
+			if	( q->con_end()->same_coords(&r->points.back()) )	// R can be reversed
+			  if	( q->con_beg()->same_coords(r->points.begin())		// Can Q be reversed instead?
+			  &&	( q == cr.roots[0] || q->is_disconnected() )		// Is Q not locked into one direction?
+			  &&	( i+1 < cr.roots.size() )				// Is there another chopped route after R?
+			  &&	(    r->points.back().same_coords(cr.roots[i+1]->points.begin())	// And does its beginning
+				  || r->points.back().same_coords(&cr.roots[i+1]->points.back()) ))	// or end link to R as-is?
+				q->set_reversed();
+			  else	r->set_reversed();
+			else if ( q->con_beg()->same_coords(&r->points.back()) )	// Q & R can both be reversed together
+			  if	( q == cr.roots[0] || q->is_disconnected() )		// as long as Q's direction is unknown
+			  {	q->set_reversed();
+				r->set_reversed();
+			  }
+			  else	flag();
+			else if ( q->con_beg()->same_coords(r->points.begin())		// Only Q can be reversed
+			     && ( q == cr.roots[0] || q->is_disconnected() ))		// as long as its direction is unknown
+				q->set_reversed();
+			else	flag();
+	  }
 }