fix roundabout-intersection on immediate exit

CHANGELOG.md

@@ -23,6 +23,7 @@
       - Fixes a bug where a bearing range of zero would cause exhaustive graph traversals
       - Fixes a bug where certain looped geometries could cause an infinite loop during extraction
       - Fixed a bug where some roads could be falsly identified as sliproads
+      - Fixed a bug where roundabout intersections could result in breaking assertions when immediately exited
     - Infrastructure:
       - Adds a feature to limit results in nearest service with a default of 100 in `osrm-routed`
 

features/guidance/roundabout-turn.feature

@@ -491,3 +491,23 @@ Feature: Basic Roundabout
            | h,a       | gh,ab,ab | depart,roundabout turn left exit-3,arrive     |
            | h,d       | gh,cd,cd | depart,roundabout turn straight exit-2,arrive |
            | h,f       | gh,ef,ef | depart,roundabout turn right exit-1,arrive    |
+
+    #http://www.openstreetmap.org/#map=19/41.03275/-2.18990
+    #at some point we probably want to recognise these situations and don't mention the roundabout at all here
+    Scenario: Enter And Exit Throughabout
+        Given the node map
+            |   |   |   |   |   | h |   |   |   |   |
+            |   |   |   |   |   |   |   |   |   |   |
+            | c | b |   | d |   |   |   | e |   | f |
+            |   |   |   |   |   |   |   |   |   |   |
+            |   | a |   |   |   | g |   |   |   |   |
+
+        And the ways
+            | nodes | highway       | name    | junction   | oneway |
+            | dghd  | tertiary_link |         | roundabout |        |
+            | cbdef | trunk         | through |            | no     |
+            | ab    | residential   | in      |            |        |
+
+        When I route I should get
+            | waypoints | turns                                                    | route                      |
+            | a,f       | depart,turn right,roundabout turn straight exit-1,arrive | in,through,through,through |

include/util/guidance/toolkit.hpp

@@ -113,7 +113,7 @@ inline bool entersRoundabout(const extractor::guidance::TurnInstruction instruct
             instruction.type == extractor::guidance::TurnType::EnterRoundaboutIntersectionAtExit ||
             instruction.type == extractor::guidance::TurnType::EnterAndExitRoundabout ||
             instruction.type == extractor::guidance::TurnType::EnterAndExitRotary ||
-            instruction.type == extractor::guidance::TurnType::EnterAndExitRotary);
+            instruction.type == extractor::guidance::TurnType::EnterAndExitRoundaboutIntersection);
 }
 
 inline bool leavesRoundabout(const extractor::guidance::TurnInstruction instruction)

src/engine/guidance/post_processing.cpp

@@ -1,5 +1,5 @@
-#include "engine/guidance/post_processing.hpp"
 #include "extractor/guidance/turn_instruction.hpp"
+#include "engine/guidance/post_processing.hpp"
 
 #include "engine/guidance/assemble_steps.hpp"
 #include "engine/guidance/lane_processing.hpp"
@@ -203,6 +203,8 @@ bool setUpRoundabout(RouteStep &step)
         instruction.type == TurnType::EnterRoundaboutAtExit ||
         instruction.type == TurnType::EnterRoundaboutIntersectionAtExit)
     {
+        // Here we consider an actual entry, not an exit. We simply have to count the additional
+        // exit
         step.maneuver.exit = 1;
         // prevent futher special case handling of these two.
         if (instruction.type == TurnType::EnterRotaryAtExit)
@@ -215,6 +217,7 @@ bool setUpRoundabout(RouteStep &step)
 
     if (leavesRoundabout(instruction))
     {
+        // This set-up, even though it looks the same, is actually looking at entering AND exiting
         step.maneuver.exit = 1; // count the otherwise missing exit
 
         // prevent futher special case handling of these two.