fix emitting invalid turn types, now surfacing due to changes in obvious detection

Conflicts:
	features/guidance/dedicated-turn-roads.feature
	include/extractor/guidance/intersection.hpp

Author: Moritz Kobitzsch

features/guidance/dedicated-turn-roads.feature

@@ -782,3 +782,40 @@ Feature: Slipways and Dedicated Turn Lanes
        When I route I should get
             | waypoints | route                         | turns                              |
             | s,g       | main,sliproad,another,another | depart,turn right,turn left,arrive |
+
+    Scenario: Sliproad before a roundabout
+        Given the node map
+            """
+                      e
+            a - b - - c - d
+                    'f|l'
+                      m
+                      g
+                      |
+                     .h-_
+                k - i    |
+                     '.j.'
+
+            """
+
+        And the ways
+            | nodes | junction   | oneway | highway   | name |
+            | ab    |            | yes    | primary   | road |
+            | bc    |            | yes    | primary   | road |
+            | cd    |            | yes    | primary   | road |
+            | ec    |            | yes    | secondary |      |
+            | cm    |            | yes    | secondary |      |
+            | mg    |            | yes    | primary   |      |
+            | gh    |            | no     | primary   |      |
+            | hijh  | roundabout | yes    | primary   |      |
+            | ik    |            | yes    | primary   |      |
+            | bfm   |            | yes    | primary   |      |
+            | gld   |            | yes    | primary   |      |
+
+        And the relations
+            | type        | way:from | way:to | node:via | restriction   |
+            | restriction | bc       | cd     | c        | only_straight |
+
+        When I route I should get
+            | waypoints | route     | turns                                                     | locations |
+            | a,k       | road,,,   | depart,continue right,roundabout turn right exit-1,arrive | a,b,h,k   |

include/extractor/guidance/intersection.hpp

@@ -34,6 +34,14 @@ struct IntersectionShapeData
 };
 
 inline auto makeCompareShapeDataByBearing(const double base_bearing)
+{
+    return [base_bearing](const auto &lhs, const auto &rhs) {
+        return util::angularDeviation(base_bearing, lhs.bearing) <
+               util::angularDeviation(base_bearing, rhs.bearing);
+    };
+}
+
+inline auto makeCompareShapeDataAngleToBearing(const double base_bearing)
 {
     return [base_bearing](const auto &lhs, const auto &rhs) {
         return util::angleBetweenBearings(base_bearing, lhs.bearing) <

src/engine/guidance/post_processing.cpp

@@ -1073,7 +1073,8 @@ std::vector<RouteStep> collapseTurns(std::vector<RouteStep> steps)
         if (one_back_step.maneuver.instruction.type == TurnType::Sliproad)
         {
             if (current_step.maneuver.instruction.type == TurnType::Suppressed &&
-                compatible(one_back_step, current_step))
+                compatible(one_back_step, current_step) && current_step.intersections.size() == 1 &&
+                current_step.intersections.front().entry.size() == 2)
             {
                 // Traffic light on the sliproad, the road itself will be handled in the next
                 // iteration, when one-back-index again points to the sliproad.

src/extractor/guidance/intersection_generator.cpp

@@ -135,8 +135,9 @@ IntersectionGenerator::ComputeIntersectionShape(const NodeID node_at_center_of_i
             }
             return util::reverseBearing(intersection.begin()->bearing);
         }();
-        std::sort(
-            intersection.begin(), intersection.end(), makeCompareShapeDataByBearing(base_bearing));
+        std::sort(intersection.begin(),
+                  intersection.end(),
+                  makeCompareShapeDataAngleToBearing(base_bearing));
     }
     return intersection;
 }