Prevent self intersecting lines without a junction node

(closes #4646)
openstreetmap · Jan 9, 2018 · e661281 · e661281
1 parent 49eb46f
commit e661281
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Showing 3 changed files with 18 additions and 10 deletions.
diff --git a/modules/behavior/draw_way.js b/modules/behavior/draw_way.js
@@ -96,7 +96,7 @@ export function behaviorDrawWay(context, wayId, index, mode, startGraph) {
 
         context.replace(actionMoveNode(end.id, loc));
         end = context.entity(end.id);
-        checkGeometry(true);    // skipLast = true
+        checkGeometry(origWay.isClosed());    // skipLast = true when drawing areas
     }
 
 
@@ -125,11 +125,9 @@ export function behaviorDrawWay(context, wayId, index, mode, startGraph) {
         for (var i = 0; i < parents.length; i++) {
             var parent = parents[i];
             var nodes = parent.nodes.map(function(nodeID) { return graph.entity(nodeID); });
-            if (parent.isClosed()) {
-                if (skipLast)  nodes.pop();   // disregard closing segment - #4655
-                if (geoHasSelfIntersections(nodes, entity.id)) {
-                    return true;
-                }
+            if (skipLast)  nodes.pop();   // disregard closing segment - #4655
+            if (geoHasSelfIntersections(nodes, entity.id)) {
+                return true;
             }
         }
 
@@ -296,7 +294,7 @@ export function behaviorDrawWay(context, wayId, index, mode, startGraph) {
     // If the way has enough nodes to be valid, it's selected.
     // Otherwise, delete everything and return to browse mode.
     drawWay.finish = function() {
-        checkGeometry(false);   // skipLast = false
+        checkGeometry(true);   // skipLast = true
         if (context.surface().classed('nope')) {
             return;   // can't click here
         }

diff --git a/modules/geo/geom.js b/modules/geo/geom.js
@@ -105,8 +105,18 @@ export function geoHasSelfIntersections(nodes, activeID) {
             if (geoVecEqual(p[1], q[0]) || geoVecEqual(p[0], q[1]) ||
                 geoVecEqual(p[0], q[0]) || geoVecEqual(p[1], q[1]) ) {
                 continue;
-            } else if (geoLineIntersection(p, q)) {
-                return true;
+            }
+
+            var hit = geoLineIntersection(p, q);
+            if (hit) {
+                var epsilon = 1e-8;
+                // skip if the hit is at the segment's endpoint
+                if (geoVecEqual(p[1], hit, epsilon) || geoVecEqual(p[0], hit, epsilon) ||
+                    geoVecEqual(q[1], hit, epsilon) || geoVecEqual(q[0], hit, epsilon) ) {
+                    continue;
+                } else {
+                    return true;
+                }
             }
         }
     }

diff --git a/modules/modes/drag_node.js b/modules/modes/drag_node.js
@@ -259,7 +259,7 @@ export function modeDragNode(context) {
 
             // If we still haven't tested this node's parent way for self-intersections.
             // (because it's not a member of a multipolygon), test it now.
-            if (activeIndex === null && parent.isClosed()) {
+            if (activeIndex === null) {
                 nodes = parent.nodes.map(function(nodeID) { return graph.entity(nodeID); });
                 if (nodes.length && geoHasSelfIntersections(nodes, entity.id)) {
                     return true;