Fix snapping target locations to ways used in turn restrictions

CHANGELOG.md

@@ -50,6 +50,7 @@
  - ADDED: Add support for non-round-trips with a single fixed endpoint. [#6050](https:/Project-OSRM/osrm-backend/pull/6050)
  - FIXED: Improvements to maneuver override processing [#6125](https:/Project-OSRM/osrm-backend/pull/6125)
  - ADDED: Support snapping to multiple ways at an input location. [#5953](https:/Project-OSRM/osrm-backend/pull/5953)
+ - FIXED: Fix snapping target locations to ways used in turn restrictions. [#6339](https:/Project-OSRM/osrm-backend/pull/6339)
 
 # 5.26.0
  - Changes from 5.25.0

features/car/multi_via_restrictions.feature

@@ -1031,3 +1031,61 @@ Feature: Car - Multiple Via Turn restrictions
  | from | to | route | locations |
  | a | f | ab,bc,cd,de,ef,ef | a,b,c,d,e,f |
 
+
+ @restriction-way
+ Scenario: Snap source/target to via restriction way
+ Given the node map
+ """
+ a-1-b-2-c-3-d
+ """
+
+ And the ways
+ | nodes |
+ | ab |
+ | bc |
+ | cd |
+
+ And the relations
+ | type | way:from | way:via | way:to | restriction |
+ | restriction | ab | bc | cd | no_straight_on |
+
+ When I route I should get
+ | from | to | route |
+ | 1 | 2 | ab,bc,bc |
+ | 2 | 3 | bc,cd,cd |
+
+
+ @restriction-way
+ Scenario: Car - Snap source/target to multi-via restriction way
+ # Example: https://www.openstreetmap.org/relation/11787041
+ Given the node map
+ """
+ |--g---f---e
+ a | 1
+ |--b---c---d
+
+ """
+
+ And the nodes
+ | node | highway |
+ | b | traffic_signals |
+
+ And the ways
+ | nodes | oneway | name |
+ | ab | yes | enter |
+ | bc | yes | enter |
+ | cd | yes | right |
+ | de | yes | up |
+ | ef | yes | left |
+ | fc | yes | down |
+ | fg | yes | exit |
+ | ga | yes | exit |
+
+ And the relations
+ | type | way:from | way:via | way:to | restriction |
+ | restriction | bc | cd,de,ef | fg | no_u_turn |
+
+ When I route I should get
+ | from | to | route | locations |
+ | a | 1 | enter,right,up,up | a,c,d,_ |
+ | 1 | a | up,left,exit,exit | _,e,f,a |

src/extractor/edge_based_graph_factory.cpp

@@ -414,6 +414,48 @@ EdgeBasedGraphFactory::GenerateEdgeExpandedNodes(const WayRestrictionMap &way_re
  // the only consumer of this mapping).
  mapping.push_back(NBGToEBG{node_u, node_v, edge_based_node_id, SPECIAL_NODEID});
 
+ // We also want to include duplicate via edges in the list of segments that
+ // an input location can snap to. Without this, it would be possible to not find
+ // certain routes that end on a via-way, because they are only routable via the
+ // duplicated edge.
+ const auto &forward_geometry = m_compressed_edge_container.GetBucketReference(eid);
+ const auto segment_count = forward_geometry.size();
+
+ NodeID current_edge_source_coordinate_id = node_u;
+ const EdgeData &forward_data = m_node_based_graph.GetEdgeData(eid);
+
+ const auto edge_id_to_segment_id = [](const NodeID edge_based_node_id) {
+ if (edge_based_node_id == SPECIAL_NODEID)
+ {
+ return SegmentID{SPECIAL_SEGMENTID, false};
+ }
+
+ return SegmentID{edge_based_node_id, true};
+ };
+
+ // Add segments of edge-based nodes
+ for (const auto i : util::irange(std::size_t{0}, segment_count))
+ {
+ const NodeID current_edge_target_coordinate_id = forward_geometry[i].node_id;
+
+ // don't add node-segments for penalties
+ if (current_edge_target_coordinate_id == current_edge_source_coordinate_id)
+ continue;
+
+ BOOST_ASSERT(current_edge_target_coordinate_id !=
+ current_edge_source_coordinate_id);
+
+ // build edges
+ m_edge_based_node_segments.emplace_back(edge_id_to_segment_id(edge_based_node_id),
+ SegmentID{SPECIAL_SEGMENTID, false},
+ current_edge_source_coordinate_id,
+ current_edge_target_coordinate_id,
+ i,
+ forward_data.flags.startpoint);
+
+ current_edge_source_coordinate_id = current_edge_target_coordinate_id;
+ }
+
  edge_based_node_id++;
  progress.PrintStatus(progress_counter++);
  }