From 73e27c96571aa7fa4470fbe8ed3528b4e8ef70ca Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Mon, 9 Jan 2017 19:41:38 -0500
Subject: [PATCH] Now that updateNode preserves circularity, provide
 close/unclose functions

This lets us break closed ways at their connecting node in the few situations where
we actually want that behavior (disconnect action for circular non-area ways)
---
 modules/actions/disconnect.js |  7 +++++--
 modules/osm/way.js            | 36 ++++++++++++++++++++++++++++++++---
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/modules/actions/disconnect.js b/modules/actions/disconnect.js
index 85f9ce454..82274234f 100644
--- a/modules/actions/disconnect.js
+++ b/modules/actions/disconnect.js
@@ -31,6 +31,9 @@ export function actionDisconnect(nodeId, newNodeId) {
             if (connection.index === 0 && way.isArea()) {
                 // replace shared node with shared node..
                 graph = graph.replace(way.replaceNode(way.nodes[0], newNode.id));
+            } else if (way.isClosed() && connection.index === way.nodes.length - 1) {
+                // replace closing node with new new node..
+                graph = graph.replace(way.unclose().addNode(newNode.id));
             } else {
                 // replace shared node with multiple new nodes..
                 graph = graph.replace(way.updateNode(newNode.id, connection.index));
@@ -52,11 +55,11 @@ export function actionDisconnect(nodeId, newNodeId) {
                 return;
             }
             if (way.isArea() && (way.nodes[0] === nodeId)) {
-                candidates.push({wayID: way.id, index: 0});
+                candidates.push({ wayID: way.id, index: 0 });
             } else {
                 way.nodes.forEach(function(waynode, index) {
                     if (waynode === nodeId) {
-                        candidates.push({wayID: way.id, index: index});
+                        candidates.push({ wayID: way.id, index: index });
                     }
                 });
             }
diff --git a/modules/osm/way.js b/modules/osm/way.js
index 5f71ca599..bd7a28b8c 100644
--- a/modules/osm/way.js
+++ b/modules/osm/way.js
@@ -188,6 +188,36 @@ _.extend(osmWay.prototype, {
     },
 
 
+    // If this way is not closed, append the beginning node to the end of the nodelist to close it.
+    close: function() {
+        if (this.isClosed() || !this.nodes.length) return this;
+
+        var nodes = this.nodes.slice();
+        nodes.push(nodes[0]);
+        nodes = nodes.filter(noRepeatNodes);
+        return this.update({ nodes: nodes });
+    },
+
+
+    // If this way is closed, remove any connector nodes from the end of the nodelist to unclose it.
+    unclose: function() {
+        if (!this.isClosed()) return this;
+
+        var nodes = this.nodes.slice(),
+            connector = this.first(),
+            i = nodes.length - 1;
+
+        // remove trailing connectors..
+        while (i > 0 && nodes.length > 1 && nodes[i] === connector) {
+            nodes.splice(i, 1);
+            i = nodes.length - 1;
+        }
+
+        nodes = nodes.filter(noRepeatNodes);
+        return this.update({ nodes: nodes });
+    },
+
+
     // Adds a node (id) in front of the node which is currently at position index.
     // If index is undefined, the node will be added to the end of the way for linear ways,
     //   or just before the final connecting node for circular ways.
@@ -207,7 +237,7 @@ _.extend(osmWay.prototype, {
         }
 
         // If this is a closed way, remove all connector nodes except the first one
-        // (there may be duplicates)
+        // (there may be duplicates) and adjust index if necessary..
         if (isClosed) {
             var connector = this.first();
 
@@ -252,7 +282,7 @@ _.extend(osmWay.prototype, {
         }
 
         // If this is a closed way, remove all connector nodes except the first one
-        // (there may be duplicates)
+        // (there may be duplicates) and adjust index if necessary..
         if (isClosed) {
             var connector = this.first();
 
@@ -316,7 +346,7 @@ _.extend(osmWay.prototype, {
             isClosed = this.isClosed();
 
         nodes = nodes
-            .filter(function(node, i, arr) { return node !== id })
+            .filter(function(node) { return node !== id; })
             .filter(noRepeatNodes);
 
         // If the way was closed before, append a connector node to keep it closed..