From ceaf065d0e86f72bb720d497de4016113a9a467d Mon Sep 17 00:00:00 2001
From: Moritz Kobitzsch <moritz@mapbox.com>
Date: Tue, 23 May 2017 11:42:23 +0200
Subject: [PATCH] don't collapse highway ramps into uturns (#4074)

---
 CHANGELOG.md                                  |  1 +
 features/car/summaries.feature                |  4 +-
 features/guidance/turn.feature                | 40 +++++++++++++++++++
 include/util/guidance/name_announcements.hpp  |  5 ++-
 .../guidance/collapse_scenario_detection.cpp  |  6 +++
 5 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a461f0d45..022516a1b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@
       - #4075 Changed counting of exits on service roundabouts
     - Bugfixes
       - Fixed a copy/paste issue assigning wrong directions in similar turns (left over right)
+      - #4074: fixed a bug that would announce entering highway ramps as u-turns
 
 # 5.7.1
     - Bugfixes
diff --git a/features/car/summaries.feature b/features/car/summaries.feature
index 27cb406e7..688f203b0 100644
--- a/features/car/summaries.feature
+++ b/features/car/summaries.feature
@@ -60,8 +60,8 @@ Feature: Basic Routing
             | bc    |      | 101 |
 
         When I route I should get
-            | waypoints | route | summary   |
-            | a,c       | road, | road, 101 |
+            | waypoints | route  | summary   |
+            | a,c       | road,, | road, 101 |
 
      Scenario: Only Refs
         Given the node map
diff --git a/features/guidance/turn.feature b/features/guidance/turn.feature
index cc39956f8..f002d67e3 100644
--- a/features/guidance/turn.feature
+++ b/features/guidance/turn.feature
@@ -1279,3 +1279,43 @@ Feature: Simple Turns
         When I route I should get
             | waypoints | route       | turns                           |
             | a,d       | foo,bar,bar | depart,turn slight right,arrive |
+
+    Scenario: UTurn onto ramp
+        Given the node map
+            """
+                       a - - - b - c
+                                  .|
+                _________________ de
+            h-g-----------------------f
+            """
+        And the ways
+            | nodes | name  | ref  | oneway | highway       |
+            | abc   | Road  |      | yes    | primary       |
+            | ce    | other |      | yes    | primary       |
+            | cdg   |       |      | yes    | motorway_link |
+            | fgh   |       | C 42 | yes    | motorway      |
+
+
+        When I route I should get
+            | waypoints | route   | ref         | turns                                         |
+            | a,h       | Road,,, | ,,C 42,C 42 | depart,on ramp right,merge slight left,arrive |
+
+    Scenario: UTurn onto ramp (same ref)
+        Given the node map
+            """
+                       a - - - b - c
+                                  .|
+                _________________ de
+            h-g-----------------------f
+            """
+        And the ways
+            | nodes | name  | ref  | oneway | highway       |
+            | abc   | Road  | C 42 | yes    | primary       |
+            | ce    | other |      | yes    | primary       |
+            | cdg   |       |      | yes    | motorway_link |
+            | fgh   |       | C 42 | yes    | motorway      |
+
+
+        When I route I should get
+            | waypoints | route           | ref             | turns                                         |
+            | a,h       | Road,,,         | C 42,,C 42,C 42 | depart,on ramp right,merge slight left,arrive |
diff --git a/include/util/guidance/name_announcements.hpp b/include/util/guidance/name_announcements.hpp
index 098a7b80a..a43706cb8 100644
--- a/include/util/guidance/name_announcements.hpp
+++ b/include/util/guidance/name_announcements.hpp
@@ -123,8 +123,9 @@ inline bool requiresNameAnnounced(const std::string &from_name,
         (names_are_equal && ref_is_removed) || is_suffix_change;
 
     const auto needs_announce =
-        // " (Ref)" -> "Name "
-        (from_name.empty() && !from_ref.empty() && !to_name.empty() && to_ref.empty());
+        // " (Ref)" -> "Name " and reverse
+        (from_name.empty() && !from_ref.empty() && !to_name.empty() && to_ref.empty()) ||
+        (!from_name.empty() && from_ref.empty() && to_name.empty() && !to_ref.empty());
 
     const auto pronunciation_changes = from_pronunciation != to_pronunciation;
 
diff --git a/src/engine/guidance/collapse_scenario_detection.cpp b/src/engine/guidance/collapse_scenario_detection.cpp
index 2f26ed190..530d353ff 100644
--- a/src/engine/guidance/collapse_scenario_detection.cpp
+++ b/src/engine/guidance/collapse_scenario_detection.cpp
@@ -147,6 +147,12 @@ bool isUTurn(const RouteStepIterator step_prior_to_intersection,
             step_prior_to_intersection, step_entering_intersection, step_leaving_intersection))
         return false;
 
+    // uturns only allowed on turns
+    if (!hasTurnType(*step_entering_intersection, TurnType::Turn) &&
+        !hasTurnType(*step_entering_intersection, TurnType::Continue) &&
+        !hasTurnType(*step_entering_intersection, TurnType::EndOfRoad))
+        return false;
+
     // the most basic condition for a uturn is that we actually turn around
     const bool takes_u_turn = bearingsAreReversed(
         util::bearing::reverse(step_entering_intersection->intersections.front()