From d2d464d9ee8c220e524bbf52c8697cd3dcc3d3c6 Mon Sep 17 00:00:00 2001
From: Martin Raifer <martin.raifer@uni-heidelberg.de>
Date: Fri, 6 Apr 2018 11:30:16 +0200
Subject: [PATCH] only drop restrictions from FROM towards VIA when adding new
 only

partially adresses bugs in #4968:

* doesn't crash anymore in complex situations (short FROM ways where both ends connect to a TO way)
* adding a only-restriction at one end of a short FROM doesn't delete restrictions on the other end of the same FROM anymore
---
 modules/osm/intersection.js       | 14 ++++++--------
 modules/ui/fields/restrictions.js |  4 ++--
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/modules/osm/intersection.js b/modules/osm/intersection.js
index 9d0b7a83c..384961f53 100644
--- a/modules/osm/intersection.js
+++ b/modules/osm/intersection.js
@@ -408,22 +408,20 @@ export function osmIntersection(graph, startVertexId, maxDistance) {
                         var isAlongOnlyPath = false;
 
                         if (t.id === way.id) {     // match VIA, TO
-                            if (v.length === 1 && v[0].type === 'node' && v[0].id === entity.id) {
-                                matchesViaTo = true;    // match VIA node
-
-                            } else {                    // match all VIA ways
+                            if (v.length === 1 && v[0].type === 'node') { // match VIA node
+                                matchesViaTo = v[0].id === entity.id;
+                            } else {                                      // match all VIA ways
                                 var pathVias = [];
-                                for (k = 1; k < currPath.length; k++) {  // k = 1 skips FROM way
-                                    if (currPath[k][0] === 'w') pathVias.push(currPath[k]);
+                                for (k = 2; k < currPath.length; k+=2) {  // k = 1 skips FROM way
+                                    pathVias.push(currPath[k]);
                                 }
                                 var restrictionVias = [];
                                 for (k = 0; k < v.length; k++) {
-                                    if (v[k].type === 'way') restrictionVias.push(v[k].id);
+                                    restrictionVias.push(v[k].id);
                                 }
                                 var diff = _difference(pathVias, restrictionVias);
                                 matchesViaTo = !diff.length;
                             }
-
                         } else if (isOnly) {
                             for (k = 0; k < v.length; k++) {
                                 // way doesn't match TO, but is one of the via ways along the path of an "only"
diff --git a/modules/ui/fields/restrictions.js b/modules/ui/fields/restrictions.js
index 23e3e0f5e..32e6e9790 100644
--- a/modules/ui/fields/restrictions.js
+++ b/modules/ui/fields/restrictions.js
@@ -359,13 +359,13 @@ export function uiFieldRestrictions(field, context) {
                     datumOnly.only = true;
                     restrictionType = restrictionType.replace(/^no/, 'only');
 
-                    // Adding an ONLY restriction should destroy all other direct restrictions from the FROM.
+                    // Adding an ONLY restriction should destroy all other direct restrictions from the FROM towards the VIA.
                     // We will remember them in _oldTurns, and restore them if the user clicks again.
                     turns = _intersection.turns(_fromWayID, 2);
                     extraActions = [];
                     _oldTurns = [];
                     for (i = 0; i < turns.length; i++) {
-                        if (turns[i].direct) {
+                        if (turns[i].direct && turns[i].path[1] === datum.path[1]) {
                             turns[i].restrictionType = osmInferRestriction(vgraph, turns[i], projection);
                             _oldTurns.push(turns[i]);
                             extraActions.push(actionUnrestrictTurn(turns[i]));