From 1abcc7fccf685e25f4c470ee24877799cdb2ab22 Mon Sep 17 00:00:00 2001
From: Quincy Morgan <quincy.morgan@icloud.com>
Date: Fri, 13 Sep 2019 15:17:48 -0400
Subject: [PATCH] Show warning for elevator nodes that are disconnected from
 the highway network (close #6812) Simplify disconnected way validation code

---
 modules/validations/disconnected_way.js | 73 ++++++++++++++-----------
 1 file changed, 41 insertions(+), 32 deletions(-)

diff --git a/modules/validations/disconnected_way.js b/modules/validations/disconnected_way.js
index b16323f25..ef1a566f4 100644
--- a/modules/validations/disconnected_way.js
+++ b/modules/validations/disconnected_way.js
@@ -110,37 +110,58 @@ export function validationDisconnectedWay() {
 
         function routingIslandForEntity(entity) {
 
-            if (entity.type !== 'way') return null;
+            var routingIsland = new Set();  // the interconnected routable features
+            var waysToCheck = [];           // the queue of remaining routable ways to traverse
 
-            if (!isRoutableWay(entity, true)) return null;
+            function queueParentWays(node) {
+                graph.parentWays(node).forEach(function(parentWay) {
+                    if (!routingIsland.has(parentWay) &&    // only check each feature once
+                        isRoutableWay(parentWay, false)) {  // only check routable features
+                        routingIsland.add(parentWay);
+                        waysToCheck.push(parentWay);
+                    }
+                });
+            }
 
-            var waysToCheck = [entity];
-            var routingIsland = new Set([entity]);
+            if (entity.type === 'way' && isRoutableWay(entity, true)) {
+
+                routingIsland.add(entity);
+                waysToCheck.push(entity);
+
+            } else if (entity.type === 'node' && isRoutableNode(entity)) {
+
+                routingIsland.add(entity);
+                queueParentWays(entity);
+
+            } else {
+                // this feature isn't routable, cannot be a routing island
+                return null;
+            }
 
             while (waysToCheck.length) {
                 var wayToCheck = waysToCheck.pop();
                 var childNodes = graph.childNodes(wayToCheck);
                 for (var i in childNodes) {
                     var vertex = childNodes[i];
-                    var result = isConnectedVertex(vertex, routingIsland);
-                    if (result === true) {
+
+                    if (isConnectedVertex(vertex)) {
+                        // found a link to the wider network, not a routing island
                         return null;
-                    } else if (result === false) {
-                        continue;
                     }
-                    result.forEach(function(connectedWay) {
-                        if (!routingIsland.has(connectedWay)) {
-                            routingIsland.add(connectedWay);
-                            waysToCheck.push(connectedWay);
-                        }
-                    });
+
+                    if (isRoutableNode(vertex)) {
+                        routingIsland.add(vertex);
+                    }
+
+                    queueParentWays(vertex);
                 }
             }
 
+            // no network link found, this is a routing island, return its members
             return routingIsland;
         }
 
-        function isConnectedVertex(vertex, routingIslandWays) {
+        function isConnectedVertex(vertex) {
             // assume ways overlapping unloaded tiles are connected to the wider road network  - #5938
             var osm = services.osm;
             if (osm && !osm.isDataLoaded(vertex.loc)) return true;
@@ -150,24 +171,12 @@ export function validationDisconnectedWay() {
                 vertex.tags.entrance !== 'no') return true;
             if (vertex.tags.amenity === 'parking_entrance') return true;
 
-            var parentsWays = graph.parentWays(vertex);
-
-            // standalone vertex
-            if (parentsWays.length === 1) return false;
-
-            var connectedWays = new Set();
-
-            for (var i in parentsWays) {
-                var parentWay = parentsWays[i];
-
-                // ignore any way we've already accounted for
-                if (routingIslandWays.has(parentWay)) continue;
-
-                if (isRoutableWay(parentWay, false)) connectedWays.add(parentWay);
-            }
-
-            if (connectedWays.size) return connectedWays;
+            return false;
+        }
 
+        function isRoutableNode(node) {
+            // treat elevators as distinct features in the highway network
+            if (node.tags.highway === 'elevator') return true;
             return false;
         }