Update changelog

Regression is due to a combination of 08248e3853
and http://www.openstreetmap.org/changeset/40938983
where in ways http://www.openstreetmap.org/way/27292481
and http://www.openstreetmap.org/way/432488408
nodes
4315134884 (part of way 432488408)
4315134891 (part of way 432488408)
4315134886 (part of way 432488408)
form a u-turn that has index 0 after sorting and used as an allowed one
with a reversed edge.
A u-turn that corresponds to the condition uturn_could_be_valid == true has index 1
and ignored.

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 5.2.8
+  - Bugfixes:
+    - Handle an edge case that cause the turn instruction code to segfault during osrm-extract on Egypt.
+
 # 5.2.7
   - Bugfixes
     - BREAKING: Fix bug that could result in failure to load 'osrm.icd' files. This breaks the dataformat

src/extractor/guidance/intersection_generator.cpp

@@ -138,7 +138,20 @@ Intersection IntersectionGenerator::getConnectedRoads(const NodeID from_node,
     const auto valid_count =
         boost::count_if(intersection, [](const ConnectedRoad &road) { return road.entry_allowed; });
     if (0 == valid_count && uturn_could_be_valid)
-        intersection[0].entry_allowed = true;
+    {
+        // after intersections sorting by angles, find the u-turn with (from_node == to_node)
+        // that was inserted together with setting uturn_could_be_valid flag
+        std::size_t self_u_turn = 0;
+        while (self_u_turn < intersection.size()
+               && intersection[self_u_turn].turn.angle < std::numeric_limits<double>::epsilon()
+               && from_node != node_based_graph.GetTarget(intersection[self_u_turn].turn.eid))
+        {
+            ++self_u_turn;
+        }
+
+        BOOST_ASSERT(from_node == node_based_graph.GetTarget(intersection[self_u_turn].turn.eid));
+        intersection[self_u_turn].entry_allowed = true;
+    }
 
     return mergeSegregatedRoads(std::move(intersection));
 }