From 076f17c241644061dcea28a4b2db089073bf3070 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sat, 9 Aug 2014 23:05:57 +0200
Subject: [PATCH 01/18] [buffer][test] change usage of join strategies for
 robustness check

---
 .../robustness/overlay/buffer/recursive_polygons_buffer.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/test/robustness/overlay/buffer/recursive_polygons_buffer.cpp b/test/robustness/overlay/buffer/recursive_polygons_buffer.cpp
index d62e83a2b..737f22c2e 100644
--- a/test/robustness/overlay/buffer/recursive_polygons_buffer.cpp
+++ b/test/robustness/overlay/buffer/recursive_polygons_buffer.cpp
@@ -200,6 +200,8 @@ bool test_buffer(MultiPolygon& result, int& index,
     bg::strategy::buffer::end_round end_strategy;
     bg::strategy::buffer::point_circle point_strategy;
     bg::strategy::buffer::side_straight side_strategy;
+    bg::strategy::buffer::join_round join_round_strategy(100); // Compatible with unit tests
+    bg::strategy::buffer::join_miter join_miter_strategy;
 
     try
     {
@@ -208,13 +210,13 @@ bool test_buffer(MultiPolygon& result, int& index,
             case 1 :
                 bg::buffer(mp, buffered,
                                 distance_strategy, side_strategy,
-                                bg::strategy::buffer::join_round(),
+                                join_round_strategy,
                                 end_strategy, point_strategy);
                 break;
             case 2 :
                 bg::buffer(mp, buffered,
                                 distance_strategy, side_strategy,
-                                bg::strategy::buffer::join_miter(),
+                                join_miter_strategy,
                                 end_strategy, point_strategy);
                 break;
             default :

From 536f6a6974aba7830a2e64604a702f01a258e30d Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sat, 9 Aug 2014 23:06:15 +0200
Subject: [PATCH 02/18] [buffer] remove unused variable

---
 .../algorithms/detail/buffer/buffered_piece_collection.hpp       | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
index 5cca314df..2039c1bd0 100644
--- a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
@@ -147,7 +147,6 @@ struct buffered_piece_collection
     int m_first_piece_index;
 
     buffered_ring_collection<buffered_ring<Ring> > offsetted_rings; // indexed by multi_index
-    std::vector< std::vector < robust_point_type > > robust_offsetted_rings;
     buffered_ring_collection<Ring> traversed_rings;
     segment_identifier current_segment_id;
 

From bdcdb5717ebc12cfc3dd0d8c35a831775f8d84d2 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sat, 9 Aug 2014 23:18:48 +0200
Subject: [PATCH 03/18] [buffer] don't check neighbor for on-border

---
 .../algorithms/detail/buffer/turn_in_piece_visitor.hpp      | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
index 182f5af6a..b4acb0d11 100644
--- a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
@@ -167,9 +167,13 @@ public:
         {
             return;
         }
+        if (geometry_code == 0 && neighbour)
+        {
+            return;
+        }
 
         Turn& mutable_turn = m_turns[turn.turn_index];
-        if (geometry_code == 0 && ! neighbour)
+        if (geometry_code)
         {
             // If it is on the border and they are neighbours, it should be
             // on the offsetted ring

From 6cf72447d1c4f981198b0cacc532eba1881b0c7f Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sat, 9 Aug 2014 23:33:15 +0200
Subject: [PATCH 04/18] [buffer][test] remove unused variable

---
 test/algorithms/buffer/multi_polygon_buffer.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index aa0f42890..5fa0a3a68 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -338,7 +338,6 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_t", rt_t, join_miter, end_flat, 15.6569, 1.0);
 }
 
-int point_buffer_count;
 
 int test_main(int, char* [])
 {

From a46e2603d8437969ed3f60ecfd09e1af48fb5f29 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sat, 9 Aug 2014 23:51:42 +0200
Subject: [PATCH 05/18] [buffer][fix] In rare cases an extra ring was traversed
 and created. Fixed, that ring is discarded now. This fixes behaviour of
 assign_parents with positive-rings in positive-rings (when
 check_for_orientation is true; normally (for overlay) it is false)

It also reverses a negative-only ring so fixes a linestring_buffer testcase.

For multi-polygon it fixes new testcase rt_u2 found by recursive-polygon-buffer test
---
 .../buffer/buffered_piece_collection.hpp      |  2 +-
 .../detail/overlay/assign_parents.hpp         | 52 +++++++++++--------
 test/algorithms/buffer/linestring_buffer.cpp  |  6 +--
 .../buffer/multi_polygon_buffer.cpp           |  9 +++-
 4 files changed, 43 insertions(+), 26 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
index 2039c1bd0..e657ff978 100644
--- a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
@@ -826,7 +826,7 @@ struct buffered_piece_collection
             selected[id] = properties(*it, true);
         }
 
-        detail::overlay::assign_parents(offsetted_rings, traversed_rings, selected, false);
+        detail::overlay::assign_parents(offsetted_rings, traversed_rings, selected, true);
         return detail::overlay::add_rings<GeometryOutput>(selected, offsetted_rings, traversed_rings, out);
     }
 
diff --git a/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp b/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp
index a7cbd038d..67b48cc47 100644
--- a/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp
+++ b/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp
@@ -127,30 +127,30 @@ struct assign_visitor
     template <typename Item>
     inline void apply(Item const& outer, Item const& inner, bool first = true)
     {
-        if (first && outer.real_area < 0)
+        if (first && outer.abs_area < inner.abs_area)
         {
-            // Reverse arguments
+            // Apply with reversed arguments
             apply(inner, outer, false);
             return;
         }
 
-        if (math::larger(outer.real_area, 0))
+        if (m_check_for_orientation
+         || (math::larger(outer.real_area, 0)
+          && math::smaller(inner.real_area, 0)))
         {
-            if (inner.real_area < 0 || m_check_for_orientation)
-            {
-                ring_info_type& inner_in_map = m_ring_map[inner.id];
+            ring_info_type& inner_in_map = m_ring_map[inner.id];
 
-                if (geometry::within(inner_in_map.point, outer.envelope)
-                   && within_selected_input(inner_in_map, outer.id, m_geometry1, m_geometry2, m_collection)
-                   )
+            if (geometry::within(inner_in_map.point, outer.envelope)
+               && within_selected_input(inner_in_map, outer.id, m_geometry1, m_geometry2, m_collection)
+               )
+            {
+                // Assign a parent if there was no earlier parent, or the newly
+                // found parent is smaller than the previous one
+                if (inner_in_map.parent.source_index == -1
+                    || outer.abs_area < inner_in_map.parent_area)
                 {
-                    // Only assign parent if that parent is smaller (or if it is the first)
-                    if (inner_in_map.parent.source_index == -1
-                        || outer.abs_area < inner_in_map.parent_area)
-                    {
-                        inner_in_map.parent = outer.id;
-                        inner_in_map.parent_area = outer.abs_area;
-                    }
+                    inner_in_map.parent = outer.id;
+                    inner_in_map.parent_area = outer.abs_area;
                 }
             }
         }
@@ -288,13 +288,21 @@ inline void assign_parents(Geometry1 const& geometry1,
             {
                 it->second.discarded = true;
             }
-            else if (it->second.parent.source_index >= 0 && it->second.get_area() > 0)
+            else if (it->second.parent.source_index >= 0
+                    && math::larger(it->second.get_area(), 0))
             {
-                // Discard positive inner ring with parent
-                it->second.discarded = true;
+                const ring_info_type& parent = ring_map[it->second.parent];
+
+                if (math::larger(parent.area, 0))
+                {
+                    // Discard positive inner ring with positive parent
+                    it->second.discarded = true;
+                }
+                // Remove parent ID from any positive inner ring
                 it->second.parent.source_index = -1;
             }
-            else if (it->second.parent.source_index < 0 && it->second.get_area() < 0)
+            else if (it->second.parent.source_index < 0
+                    && math::smaller(it->second.get_area(), 0))
             {
                 // Reverse negative ring without parent
                 it->second.reversed = true;
@@ -313,6 +321,8 @@ inline void assign_parents(Geometry1 const& geometry1,
     }
 }
 
+
+// Version for one geometry (called by buffer)
 template
 <
     typename Geometry,
@@ -324,7 +334,7 @@ inline void assign_parents(Geometry const& geometry,
             RingMap& ring_map,
             bool check_for_orientation)
 {
-    // Call it with an empty geometry
+    // Call it with an empty geometry as second geometry (source_id == 1)
     // (ring_map should be empty for source_id==1)
 
     Geometry empty;
diff --git a/test/algorithms/buffer/linestring_buffer.cpp b/test/algorithms/buffer/linestring_buffer.cpp
index eaff55e67..bdca6e3d0 100644
--- a/test/algorithms/buffer/linestring_buffer.cpp
+++ b/test/algorithms/buffer/linestring_buffer.cpp
@@ -64,9 +64,9 @@ void test_all()
     //    test_one<linestring, polygon>("simplex_asym_neg", simplex, join_miter, end_round, 3.202, +1.5, -1.0);
     //    test_one<linestring, polygon>("simplex_asym_pos", simplex, join_miter, end_round, 3.202, -1.0, +1.5);
 
-    // Generates a reverse polygon, with a negative area, which will be made empty TODO decide about this
-    test_one<linestring, polygon>("simplex_asym_neg_rev", simplex, join_miter, end_flat, 0, +1.0, -1.5);
-    test_one<linestring, polygon>("simplex_asym_pos_rev", simplex, join_miter, end_flat, 0, -1.5, +1.0);
+    // Generates (initially) a reversed polygon, with a negative area, which is reversed afterwards in assign_parents
+    test_one<linestring, polygon>("simplex_asym_neg_rev", simplex, join_miter, end_flat, 3.202, +1.0, -1.5);
+    test_one<linestring, polygon>("simplex_asym_pos_rev", simplex, join_miter, end_flat, 3.202, -1.5, +1.0);
 
     test_one<linestring, polygon>("straight", straight, join_round, end_flat, 38.4187, 1.5, 1.5);
     test_one<linestring, polygon>("straight", straight, join_miter, end_flat, 38.4187, 1.5, 1.5);
diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index 5fa0a3a68..5001b8ef7 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -217,7 +217,12 @@ static std::string const rt_s2
 static std::string const rt_t
     = "MULTIPOLYGON(((1 3,1 4,2 3,1 3)),((1 4,0 3,0 4,0 5,1 4)))";
 
+// Creates traversed ring
+static std::string const rt_u1
+    = "MULTIPOLYGON(((7 6,8 7,8 6,7 6)),((8 9,9 10,9 9,8 9)),((2 8,3 9,3 8,2 8)),((6 5,6 6,7 6,6 5)),((6 7,7 7,6 6,5 6,6 7)),((7 7,7 8,8 7,7 7)),((6 7,6 8,7 8,6 7)),((8 7,8 8,9 8,9 7,8 7)))";
 
+static std::string const rt_u2
+    = "MULTIPOLYGON(((4 2,5 3,5 2,4 2)),((6 4,6 5,7 5,6 4)),((7 4,7 5,8 5,7 4)),((7 3,7 4,8 3,7 3)),((7 10,8 10,7 9,6 9,7 10)),((0 7,0 8,1 7,0 7)),((6 1,6 2,7 2,7 1,6 1)),((5 7,5 8,6 9,6 8,7 9,7 8,7 7,6 6,6 7,5 7)),((5 4,6 4,6 3,5 3,4 3,4 4,5 4)),((5 2,6 2,5 1,4 0,3 0,4 1,3 1,3 2,3 3,4 3,4 2,4.5 1.5,5 2)),((5 6,5 5,4 5,4 6,4 7,5 7,5 6)),((5 0,5 1,5.5 0.5,6 1,6 0,5 0)),((5 9,5 8,4 8,3 8,2 8,1 8,0 8,1 9,1 10,2 9,2 10,3 10,4 10,5 10,5 9)),((4 5,4 4,3 4,3 3,2 3,1 3,0 3,0 4,0 5,0 6,1 6,2 5,1 5,1 4,2 4,3 5,2 5,2 6,2.5 5.5,3 6,4 5)),((3 2,2 2,2 3,3 2)),((2 0,1 0,2 1,3 0,2 0)),((1 1,0 1,0 2,0 3,1 2,1.5 1.5,2 2,3 1,2 1,1 1)),((2 6,1 6,1 7,2 7,3 7,2 6)),((4 8,4 7,3 7,4 8)),((9 6,8 6,7 6,7 7,8 7,8.5 6.5,9 7,8 7,8 8,8.5 7.5,9 8,8 8,8 9,9 9,9 10,10 10,10 9,10 8,10 7,10 6,10 5,9 4,9 5,8 5,9 6)),((7 0,6 0,7 1,8 1,7 0)),((8 3,9 2,8 2,7 2,8 3)),((10 2,10 1,10 0,9 0,9 1,8 1,8 2,8.5 1.5,9 2,9 3,10 4,10 3,10 2)),((9 4,9 3,8 3,8 4,9 4)))";
 
 
 template <typename P>
@@ -336,8 +341,10 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_s1", rt_s1, join_miter, end_flat, 20.4853, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_s2", rt_s2, join_miter, end_flat, 24.6495, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_t", rt_t, join_miter, end_flat, 15.6569, 1.0);
-}
 
+    test_one<multi_polygon_type, polygon_type>("rt_u1", rt_u1, join_round, end_flat, 33.2032, 1.0);
+    test_one<multi_polygon_type, polygon_type>("rt_u2", rt_u2, join_round, end_flat, 138.8001, 1.0);
+}
 
 int test_main(int, char* [])
 {

From 468c3dd36a9a38370ed715c74c7fa7513f5886a7 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 00:03:15 +0200
Subject: [PATCH 06/18] [buffer][test] clean up old comments/cases

---
 test/algorithms/buffer/multi_polygon_buffer.cpp | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index 5001b8ef7..06feebee2 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -249,9 +249,6 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("multi_simplex_50", simplex, join_round, end_flat, 174.46, 5.0);
     test_one<multi_polygon_type, polygon_type>("multi_simplex_50", simplex, join_miter, end_flat, 298.797, 5.0);
 
-    // This one does not work:
-    // test_one<multi_polygon_type, buf::join_round_by_divide, polygon_type>("multi_simplex_50", simplex, 'd', 174.46, 5.0);
-    
     test_one<multi_polygon_type, polygon_type>("zonethru_05", zonethru, join_round, end_flat, 67.4627, 0.5);
     test_one<multi_polygon_type, polygon_type>("zonethru_05", zonethru, join_miter, end_flat, 68.0000, 0.5);
     test_one<multi_polygon_type, polygon_type>("zonethru_10", zonethru, join_round, end_flat, 93.8508, 1.0);
@@ -265,9 +262,7 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("wrapped_15", wrapped, join_round, end_flat, 167.066, 1.5);
     test_one<multi_polygon_type, polygon_type>("wrapped_15", wrapped, join_miter, end_flat, 169.000, 1.5);
 
-    // TODO: there is still an undetected hole inside rt_a
     test_one<multi_polygon_type, polygon_type>("rt_a", rt_a, join_round, end_flat, 34.5381, 1.0);
-
     test_one<multi_polygon_type, polygon_type>("rt_a", rt_a, join_miter, end_flat, 36, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_b", rt_b, join_round, end_flat, 31.4186, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_b", rt_b, join_miter, end_flat, 34, 1.0);
@@ -277,7 +272,6 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_d", rt_d, join_miter, end_flat, 19.8823, 0.3);
     test_one<multi_polygon_type, polygon_type>("rt_e", rt_e, join_round, end_flat, 14.1866, 0.3);
     test_one<multi_polygon_type, polygon_type>("rt_e", rt_e, join_miter, end_flat, 15.1198, 0.3);
-    // This does not add anything: test_one<multi_polygon_type, polygon_type>("rt_f", rt_f, join_round, end_flat, 4.28937, 0.3);
 
     test_one<multi_polygon_type, polygon_type>("rt_f", rt_f, join_miter, end_flat, 4.60853, 0.3);
 
@@ -294,13 +288,11 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_j", rt_j, join_miter, end_flat, 35.1421, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_k", rt_k, join_round, end_flat, 42.0092, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_k", rt_k, join_miter, end_flat, 48.0563, 1.0);
-    // This does not add anything: test_one<multi_polygon_type, polygon_type>("rt_l", rt_l, join_round, end_flat, 14.1074, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_l", rt_l, join_miter, end_flat, 19.3995, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_m1", rt_m1, join_round, end_flat, 14.1074, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_m1", rt_m1, join_miter, end_flat, 19.4853, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_m2", rt_m2, join_miter, end_flat, 21.4853, 1.0);
 
-    // This does not add anything: test_one<multi_polygon_type, polygon_type>("rt_n", rt_n,  join_round, end_flat, 14.1074, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_n", rt_n,  join_miter, end_flat, 18.4853, 1.0);
 
     test_one<multi_polygon_type, polygon_type>("rt_o1", rt_o1, join_round, end_flat, 17.536, 1.0);

From b469509bd09fcc4753a75db0752d260c3d371b4e Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 12:48:22 +0200
Subject: [PATCH 07/18] [buffer][fix] Fix accidental removal of == 0

---
 .../algorithms/detail/buffer/turn_in_piece_visitor.hpp        | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
index b4acb0d11..9e652bec5 100644
--- a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
@@ -173,9 +173,9 @@ public:
         }
 
         Turn& mutable_turn = m_turns[turn.turn_index];
-        if (geometry_code)
+        if (geometry_code == 0)
         {
-            // If it is on the border and they are neighbours, it should be
+            // If it is on the border and they are not neighbours, it should be
             // on the offsetted ring
 
             if (! on_offsetted(turn.robust_point, piece))

From 6df7738d3a0ec85ab76764381d47ec4829b97973 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 12:49:37 +0200
Subject: [PATCH 08/18] [buffer][fix] Fix turns which were only on
 helper-segments, they can be discarded. This fixes rt_u3 and rt_u4 where a
 false interior ring was generated

---
 .../detail/buffer/buffered_piece_collection.hpp           | 5 +++++
 test/algorithms/buffer/multi_polygon_buffer.cpp           | 8 ++++++++
 2 files changed, 13 insertions(+)

diff --git a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
index e657ff978..425f14168 100644
--- a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
@@ -338,6 +338,10 @@ struct buffered_piece_collection
         for (typename boost::range_iterator<turn_vector_type>::type it =
             boost::begin(m_turns); it != boost::end(m_turns); ++it)
         {
+            if (it->count_on_helper > 0)
+            {
+                it->location = inside_buffer;
+            }
             if (it->count_within > 0)
             {
                 // Within can have in rare cases a rounding issue. We don't discard this
@@ -345,6 +349,7 @@ struct buffered_piece_collection
                 // will never start a new ring from this type of points.
                 it->selectable_start = false;
             }
+
         }
     }
 
diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index 06feebee2..8bdc8900f 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -224,6 +224,12 @@ static std::string const rt_u1
 static std::string const rt_u2
     = "MULTIPOLYGON(((4 2,5 3,5 2,4 2)),((6 4,6 5,7 5,6 4)),((7 4,7 5,8 5,7 4)),((7 3,7 4,8 3,7 3)),((7 10,8 10,7 9,6 9,7 10)),((0 7,0 8,1 7,0 7)),((6 1,6 2,7 2,7 1,6 1)),((5 7,5 8,6 9,6 8,7 9,7 8,7 7,6 6,6 7,5 7)),((5 4,6 4,6 3,5 3,4 3,4 4,5 4)),((5 2,6 2,5 1,4 0,3 0,4 1,3 1,3 2,3 3,4 3,4 2,4.5 1.5,5 2)),((5 6,5 5,4 5,4 6,4 7,5 7,5 6)),((5 0,5 1,5.5 0.5,6 1,6 0,5 0)),((5 9,5 8,4 8,3 8,2 8,1 8,0 8,1 9,1 10,2 9,2 10,3 10,4 10,5 10,5 9)),((4 5,4 4,3 4,3 3,2 3,1 3,0 3,0 4,0 5,0 6,1 6,2 5,1 5,1 4,2 4,3 5,2 5,2 6,2.5 5.5,3 6,4 5)),((3 2,2 2,2 3,3 2)),((2 0,1 0,2 1,3 0,2 0)),((1 1,0 1,0 2,0 3,1 2,1.5 1.5,2 2,3 1,2 1,1 1)),((2 6,1 6,1 7,2 7,3 7,2 6)),((4 8,4 7,3 7,4 8)),((9 6,8 6,7 6,7 7,8 7,8.5 6.5,9 7,8 7,8 8,8.5 7.5,9 8,8 8,8 9,9 9,9 10,10 10,10 9,10 8,10 7,10 6,10 5,9 4,9 5,8 5,9 6)),((7 0,6 0,7 1,8 1,7 0)),((8 3,9 2,8 2,7 2,8 3)),((10 2,10 1,10 0,9 0,9 1,8 1,8 2,8.5 1.5,9 2,9 3,10 4,10 3,10 2)),((9 4,9 3,8 3,8 4,9 4)))";
 
+static std::string const rt_u3
+    = "MULTIPOLYGON(((3 0,4 1,4 0,3 0)),((2 0,2 1,3 1,2 0)),((6 7,7 8,7 7,6 7)),((1 2,2 3,2 2,1 2)),((9 1,10 2,10 1,9 1)),((0 2,0 3,1 3,1 2,0 2)),((5 0,5 1,6 1,6 0,5 0)),((1 1,2 2,2 1,1 1)),((0 7,0 8,1 7,0 7)),((9 0,10 1,10 0,9 0)),((0 5,0 6,1 6,1 5,0 5)),((1 6,2 7,2 6,1 6)),((7 0,8 1,8 0,7 0)),((8 6,9 7,9 6,8 6)),((9 6,10 7,10 6,9 6)),((1 4,1 5,2 5,1 4)),((5 6,4 5,4 6,5 7,5 6)),((5 4,4.5 3.5,5 3,4 3,4 2,3 1,3 2,3 3,2 3,2 4,3 4,4 4,5 5,5 4)),((4 7,3 7,3 8,4 9,5 10,6 10,6 9,5 9,4 8,5 8,4 7)),((6 3,5 3,5 4,5.5 3.5,6 4,7 4,7 3,8 3,8 2,8 1,7 1,6 1,6 2,6 3)),((3 5,2 4,2 5,2 6,3 5)),((1 1,1 0,0 0,0 1,1 2,1 1)),((2 9,2 8,1 8,0 8,1 9,1 10,1.5 9.5,2 10,2.5 9.5,3 10,3 9,2 9)),((6 5,6 6,7 7,8 7,8 6,7 6,7 5,6 4,6 5)),((7 8,6 8,6 9,7 9,8 8,7 8)),((9 10,10 10,10 9,10 8,9 7,9 8,8 8,9 9,8 9,8 10,9 10)))";
+
+static std::string const rt_u4
+    = "MULTIPOLYGON(((5 0,6 1,6 0,5 0)),((6 1,6 2,7 2,7 1,6 1)),((6 6,7 7,7 6,6 6)),((4 7,4 8,5 8,4 7)),((1 6,1 7,2 7,1 6)),((3 4,3 5,4 5,3 4)),((2 0,2 1,3 0,2 0)),((7 2,7 3,8 3,7 2)),((3 3,4 4,4 3,3 3)),((5 9,5 10,6 10,7 10,6 9,5 8,5 9)),((5 4,5 5,6 4,5 4)),((3 1,4 2,4 1,3 1)),((3 0,3 1,4 0,3 0)),((2 7,2 8,3 8,3 7,2 7)),((9 2,9 3,10 2,9 2)),((6 2,6 3,7 3,6 2)),((8 8,9 9,9 8,8 8)),((2 1,2 2,3 2,3 1,2 1)),((4 3,5 4,5 3,4 3)),((4 6,5 7,5 6,4 6)),((1 8,1 9,2 8,1 7,1 8)),((8 8,9 7,8 7,7 7,7 8,8 8)),((8 1,8 2,9 2,9 1,10 1,9 0,8 0,8 1)),((5 2,4 2,4 3,5 2)),((2 5,1 5,1 6,2 6,3 5,2 5)),((1 3,2 4,2 3,2 2,1 1,0 1,1 2,1 3)),((1 0,0 0,1 1,2 1,1.5 0.5,2 0,1 0)),((2 10,3 10,4 10,4 9,3 9,2 8,2 9,1 9,0 9,1 10,2 10)),((9 5,9 6,10 6,10 5,10 4,9 4,8.5 3.5,9 3,8 3,8 4,7 4,7 5,8 5,9 5)),((7 0,6 0,7 1,8 1,7 0)),((7 9,7 8,6 8,6 9,7 9)))";
+
 
 template <typename P>
 void test_all()
@@ -336,6 +342,8 @@ void test_all()
 
     test_one<multi_polygon_type, polygon_type>("rt_u1", rt_u1, join_round, end_flat, 33.2032, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u2", rt_u2, join_round, end_flat, 138.8001, 1.0);
+    test_one<multi_polygon_type, polygon_type>("rt_u3", rt_u3, join_round, end_flat, 133.4526, 1.0);
+    test_one<multi_polygon_type, polygon_type>("rt_u4", rt_u4, join_round, end_flat, 126.9268, 1.0);
 }
 
 int test_main(int, char* [])

From 31abd20829dc4dbd394ad10b4cfdac34aa06f40f Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 14:15:04 +0200
Subject: [PATCH 09/18] [buffer][fix] Distinguish between "within" and
 "within_near_offsetted" The last one might be offsetted by 1 due to integer
 rounding. It is not selectable as a starting point but may be used for
 traversal

---
 .../detail/buffer/buffer_policies.hpp         |  4 +
 .../buffer/buffered_piece_collection.hpp      |  4 +-
 .../detail/buffer/turn_in_piece_visitor.hpp   | 87 +++++++++++++++++--
 .../buffer/multi_polygon_buffer.cpp           |  4 +
 test/algorithms/buffer/test_buffer.hpp        |  6 +-
 5 files changed, 95 insertions(+), 10 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/buffer_policies.hpp b/include/boost/geometry/algorithms/detail/buffer/buffer_policies.hpp
index c37f32fd7..43d54fecf 100644
--- a/include/boost/geometry/algorithms/detail/buffer/buffer_policies.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/buffer_policies.hpp
@@ -126,6 +126,9 @@ struct buffer_turn_info
     int count_within;
     int count_on_offsetted;
     int count_on_helper;
+    int count_within_near_offsetted;
+
+    // Obsolete:
     int count_on_occupied;
     int count_on_multi;
 
@@ -135,6 +138,7 @@ struct buffer_turn_info
         , count_within(0)
         , count_on_offsetted(0)
         , count_on_helper(0)
+        , count_within_near_offsetted(0)
         , count_on_occupied(0)
         , count_on_multi(0)
     {}
diff --git a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
index 425f14168..1c082ac98 100644
--- a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
@@ -338,11 +338,11 @@ struct buffered_piece_collection
         for (typename boost::range_iterator<turn_vector_type>::type it =
             boost::begin(m_turns); it != boost::end(m_turns); ++it)
         {
-            if (it->count_on_helper > 0)
+            if (it->count_within > 0)
             {
                 it->location = inside_buffer;
             }
-            if (it->count_within > 0)
+            if (it->count_within_near_offsetted > 0)
             {
                 // Within can have in rare cases a rounding issue. We don't discard this
                 // point, so it can be used to continue started rings in traversal. But
diff --git a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
index 9e652bec5..d43a01dcf 100644
--- a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
@@ -83,6 +83,44 @@ class turn_in_piece_visitor
         return true;
     }
 
+    // TODO: see comment below, this adaption of distance_projected_point can be removed
+    template <typename Point>
+    static inline boost::long_long_type distance_from_segment(Point const& subject, Point const& p, Point const& q)
+    {
+        typedef Point vector_type;
+        typedef typename geometry::coordinate_type<Point>::type coordinate_type;
+
+        vector_type v = q;
+        vector_type w = subject;
+        subtract_point(v, p);
+        subtract_point(w, p);
+
+        coordinate_type const zero = coordinate_type();
+        coordinate_type const c1 = dot_product(w, v);
+
+        if (c1 < zero)
+        {
+            // Any value above 2 is fine in this case
+            return 99999;
+        }
+        coordinate_type const c2 = dot_product(v, v);
+        if (c2 < c1 || c2 <= zero)
+        {
+            return 99999;
+        }
+
+        multiply_value(v, c1);
+        divide_value(v, c2);
+
+        Point projected = p;
+        subtract_point(v, projected);
+        subtract_point(w, projected);
+
+        add_point(projected, v);
+
+        return dot_product(subject, projected);
+    }
+
 
     template <typename Point, typename Piece>
     inline bool on_offsetted(Point const& point, Piece const& piece) const
@@ -105,11 +143,37 @@ class turn_in_piece_visitor
                     return true;
                 }
             }
-
         }
         return false;
     }
 
+    template <typename Point, typename Piece>
+    inline boost::long_long_type
+        comparable_distance_from_offsetted(Point const& point, Piece const& piece) const
+    {
+        // TODO: replace this by the code below if that is fixed for boost::long_long_type
+        // with these contents of values
+        boost::long_long_type result = 0;
+        for (int i = 1; i < piece.offsetted_count; i++)
+        {
+            Point const& previous = piece.robust_ring[i - 1];
+            Point const& current = piece.robust_ring[i];
+            boost::long_long_type dist = distance_from_segment(point, previous, current);
+            if (i == 1 || dist < result)
+            {
+                result = dist;
+            }
+        }
+        return result;
+
+        /*
+        geometry::model::linestring<Point> ls;
+        std::copy(piece.robust_ring.begin(), piece.robust_ring.begin() + piece.offsetted_count, std::back_inserter(ls));
+        typename default_comparable_distance_result<Point, Point>::type
+            const result = geometry::comparable_distance(point, ls);
+        return result;
+        */
+    }
 
 public:
 
@@ -184,14 +248,27 @@ public:
                 // Then it is somewhere on the helper-segments
                 // Classify it as inside
                 geometry_code = 1;
-                mutable_turn.count_on_helper++;
+                mutable_turn.count_on_helper++; // can still become "near_offsetted"
+            }
+            else
+            {
+                mutable_turn.count_on_offsetted++; // value is not used anymore
             }
         }
 
-        switch (geometry_code)
+        if (geometry_code == 1)
         {
-            case 1 : mutable_turn.count_within++; break;
-            case 0 : mutable_turn.count_on_offsetted++; break;
+            if (comparable_distance_from_offsetted(turn.robust_point, piece) >= 2)
+            {
+                // This is too far from the border, it counts as really inside
+                mutable_turn.count_within++;
+            }
+            else
+            {
+                // Other points count as still "on border" because they might be
+                // travelled through, but not used as starting point
+                mutable_turn.count_within_near_offsetted++;
+            }
         }
     }
 };
diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index 8bdc8900f..4e1a73cfb 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -230,6 +230,9 @@ static std::string const rt_u3
 static std::string const rt_u4
     = "MULTIPOLYGON(((5 0,6 1,6 0,5 0)),((6 1,6 2,7 2,7 1,6 1)),((6 6,7 7,7 6,6 6)),((4 7,4 8,5 8,4 7)),((1 6,1 7,2 7,1 6)),((3 4,3 5,4 5,3 4)),((2 0,2 1,3 0,2 0)),((7 2,7 3,8 3,7 2)),((3 3,4 4,4 3,3 3)),((5 9,5 10,6 10,7 10,6 9,5 8,5 9)),((5 4,5 5,6 4,5 4)),((3 1,4 2,4 1,3 1)),((3 0,3 1,4 0,3 0)),((2 7,2 8,3 8,3 7,2 7)),((9 2,9 3,10 2,9 2)),((6 2,6 3,7 3,6 2)),((8 8,9 9,9 8,8 8)),((2 1,2 2,3 2,3 1,2 1)),((4 3,5 4,5 3,4 3)),((4 6,5 7,5 6,4 6)),((1 8,1 9,2 8,1 7,1 8)),((8 8,9 7,8 7,7 7,7 8,8 8)),((8 1,8 2,9 2,9 1,10 1,9 0,8 0,8 1)),((5 2,4 2,4 3,5 2)),((2 5,1 5,1 6,2 6,3 5,2 5)),((1 3,2 4,2 3,2 2,1 1,0 1,1 2,1 3)),((1 0,0 0,1 1,2 1,1.5 0.5,2 0,1 0)),((2 10,3 10,4 10,4 9,3 9,2 8,2 9,1 9,0 9,1 10,2 10)),((9 5,9 6,10 6,10 5,10 4,9 4,8.5 3.5,9 3,8 3,8 4,7 4,7 5,8 5,9 5)),((7 0,6 0,7 1,8 1,7 0)),((7 9,7 8,6 8,6 9,7 9)))";
 
+static std::string const rt_u5
+    = "MULTIPOLYGON(((4 3,4 4,5 4,5 3,4 3)),((6 5,6 6,7 6,6 5)),((5 4,6 5,6 4,5 4)),((4 0,4 1,5 1,5 0,4 0)),((7 8,8 9,8 8,7 8)),((8 2,8 3,9 3,8 2)),((2 1,2 2,3 1,2 1)),((5 7,5 8,6 8,5 7)),((4 5,4 6,5 5,4 5)),((7 0,8 1,8 0,7 0)),((7 2,8 1,7 1,6 1,7 2)),((3 3,4 3,4 2,3 2,3 3)),((3 9,3 10,4 9,3 9)),((1 2,2 3,2 2,1 2)),((2 4,2 5,3 4,2 3,2 4)),((3 7,4 7,3 6,2 6,3 7)))";
+
 
 template <typename P>
 void test_all()
@@ -344,6 +347,7 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_u2", rt_u2, join_round, end_flat, 138.8001, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u3", rt_u3, join_round, end_flat, 133.4526, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u4", rt_u4, join_round, end_flat, 126.9268, 1.0);
+    test_one<multi_polygon_type, polygon_type>("rt_u5", rt_u5, join_round, end_flat, 78.4906, 1.0);
 }
 
 int test_main(int, char* [])
diff --git a/test/algorithms/buffer/test_buffer.hpp b/test/algorithms/buffer/test_buffer.hpp
index cd6685d95..16b76d144 100644
--- a/test/algorithms/buffer/test_buffer.hpp
+++ b/test/algorithms/buffer/test_buffer.hpp
@@ -138,10 +138,10 @@ struct svg_visitor
             out << " " << bg::method_char(it->method)
                 << ":" << bg::operation_char(it->operations[0].operation)
                 << "/" << bg::operation_char(it->operations[1].operation);
-            out << " " << (!it->selectable_start ? "w" : "")
-                << (it->count_on_multi > 0 ? "m" : "")
-                << (it->count_on_occupied > 0 ? "o" : "")
+            out << " "
                 << (it->count_on_offsetted > 0 ? "b" : "") // b: offsetted border
+                << (it->count_within_near_offsetted > 0 ? "n" : "")
+                << (it->count_within > 0 ? "w" : "")
                 << (it->count_on_helper > 0 ? "h" : "")
                 ;
 

From a7764c1b9ea9455a77b55b49f9ae024adbbfda1a Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 15:32:07 +0200
Subject: [PATCH 10/18] [buffer][fix] use taxicab distance instead of
 comparable distance This is faster and avoids overflows. This fixes rt_u6

---
 .../detail/buffer/turn_in_piece_visitor.hpp   | 40 +++++++++++++------
 .../buffer/multi_polygon_buffer.cpp           |  5 +++
 2 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
index d43a01dcf..fa08c9cd2 100644
--- a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
@@ -56,6 +56,8 @@ class turn_in_piece_visitor
     Turns& m_turns; // because partition is currently operating on const input only
     Pieces const& m_pieces; // to check for piece-type
 
+    typedef boost::long_long_type calculation_type;
+
     template <typename Point>
     static inline bool projection_on_segment(Point const& subject, Point const& p, Point const& q)
     {
@@ -83,9 +85,17 @@ class turn_in_piece_visitor
         return true;
     }
 
+    template <typename Point>
+    static inline calculation_type taxicab_distance(Point const& p, Point const& q)
+    {
+        return math::abs(geometry::get<0>(p) - geometry::get<0>(q))
+             + math::abs(geometry::get<1>(p) - geometry::get<1>(q));
+    }
+
+
     // TODO: see comment below, this adaption of distance_projected_point can be removed
     template <typename Point>
-    static inline boost::long_long_type distance_from_segment(Point const& subject, Point const& p, Point const& q)
+    static inline calculation_type taxicab_distance_from_segment(Point const& subject, Point const& p, Point const& q)
     {
         typedef Point vector_type;
         typedef typename geometry::coordinate_type<Point>::type coordinate_type;
@@ -98,15 +108,14 @@ class turn_in_piece_visitor
         coordinate_type const zero = coordinate_type();
         coordinate_type const c1 = dot_product(w, v);
 
-        if (c1 < zero)
+        if (c1 <= zero)
         {
-            // Any value above 2 is fine in this case
-            return 99999;
+            return taxicab_distance(subject, p);
         }
         coordinate_type const c2 = dot_product(v, v);
-        if (c2 < c1 || c2 <= zero)
+        if (c2 <= c1)
         {
-            return 99999;
+            return taxicab_distance(subject, q);
         }
 
         multiply_value(v, c1);
@@ -118,7 +127,9 @@ class turn_in_piece_visitor
 
         add_point(projected, v);
 
-        return dot_product(subject, projected);
+        // The dot-product still overflows for boost::long_long_type with
+        // these values (should not occur, TODO: fix this)
+        return taxicab_distance(subject, projected);
     }
 
 
@@ -148,17 +159,18 @@ class turn_in_piece_visitor
     }
 
     template <typename Point, typename Piece>
-    inline boost::long_long_type
-        comparable_distance_from_offsetted(Point const& point, Piece const& piece) const
+    inline calculation_type
+        taxicab_distance_from_offsetted(Point const& point, Piece const& piece) const
     {
         // TODO: replace this by the code below if that is fixed for boost::long_long_type
         // with these contents of values
-        boost::long_long_type result = 0;
+        calculation_type result = 0;
         for (int i = 1; i < piece.offsetted_count; i++)
         {
             Point const& previous = piece.robust_ring[i - 1];
             Point const& current = piece.robust_ring[i];
-            boost::long_long_type dist = distance_from_segment(point, previous, current);
+            calculation_type const dist
+                    = taxicab_distance_from_segment(point, previous, current);
             if (i == 1 || dist < result)
             {
                 result = dist;
@@ -258,9 +270,11 @@ public:
 
         if (geometry_code == 1)
         {
-            if (comparable_distance_from_offsetted(turn.robust_point, piece) >= 2)
+            calculation_type const distance
+                = taxicab_distance_from_offsetted(turn.robust_point, piece);
+            if (distance >= 2)
             {
-                // This is too far from the border, it counts as really inside
+                // This is too far from the border, it counts as "really within"
                 mutable_turn.count_within++;
             }
             else
diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index 4e1a73cfb..e6293b62f 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -233,6 +233,10 @@ static std::string const rt_u4
 static std::string const rt_u5
     = "MULTIPOLYGON(((4 3,4 4,5 4,5 3,4 3)),((6 5,6 6,7 6,6 5)),((5 4,6 5,6 4,5 4)),((4 0,4 1,5 1,5 0,4 0)),((7 8,8 9,8 8,7 8)),((8 2,8 3,9 3,8 2)),((2 1,2 2,3 1,2 1)),((5 7,5 8,6 8,5 7)),((4 5,4 6,5 5,4 5)),((7 0,8 1,8 0,7 0)),((7 2,8 1,7 1,6 1,7 2)),((3 3,4 3,4 2,3 2,3 3)),((3 9,3 10,4 9,3 9)),((1 2,2 3,2 2,1 2)),((2 4,2 5,3 4,2 3,2 4)),((3 7,4 7,3 6,2 6,3 7)))";
 
+static std::string const rt_u6
+    = "MULTIPOLYGON(((2 2,3 3,3 2,2 2)),((9 8,9 9,10 9,10 8,9 8)),((5 3,6 4,6 3,5 3)),((5 5,5 6,6 6,5 5)),((5 1,6 2,6 1,5 1)),((6 5,7 6,7 5,6 5)),((3 0,4 1,4 0,3 0)),((6 6,6 7,7 6,6 6)),((9 2,10 2,10 1,9 1,9 2)),((6 8,6 9,7 9,7 8,6 8)),((7 0,7 1,8 0,7 0)),((4 4,4 5,5 5,4 4)),((0 7,0 8,1 8,0 7)),((5 9,6 10,6 9,5 9)),((4 9,4 10,5 10,5 9,4 9)),((3 7,4 7,3 6,2 6,3 7)),((9 7,10 6,9 6,8 6,9 7)),((5 3,5 2,4 2,4 3,4 4,5 4,5 3)),((1 1,2 0,1 0,0 0,1 1)),((2 10,3 10,3 9,2 9,1 9,1 10,2 10)),((8.5 4.5,9 4,8 4,7 4,8 5,9 5,8.5 4.5)),((8 3,9 3,9 2,8 2,8 3)))";
+
+
 
 template <typename P>
 void test_all()
@@ -348,6 +352,7 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_u3", rt_u3, join_round, end_flat, 133.4526, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u4", rt_u4, join_round, end_flat, 126.9268, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u5", rt_u5, join_round, end_flat, 78.4906, 1.0);
+    test_one<multi_polygon_type, polygon_type>("rt_u6", rt_u6, join_round, end_flat, 115.4461, 1.0);
 }
 
 int test_main(int, char* [])

From 9c3ca1e69abef49b5b6f973de646bfb56600a870 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 15:32:46 +0200
Subject: [PATCH 11/18] [buffer][test] improve piece labelling on round joins

---
 test/algorithms/buffer/test_buffer.hpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/algorithms/buffer/test_buffer.hpp b/test/algorithms/buffer/test_buffer.hpp
index 16b76d144..a7d629779 100644
--- a/test/algorithms/buffer/test_buffer.hpp
+++ b/test/algorithms/buffer/test_buffer.hpp
@@ -208,10 +208,11 @@ struct svg_visitor
                 std::ostringstream out;
                 out << piece.index << "/" << int(piece.type) << "/" << piece.first_seg_id.segment_index << ".." << piece.last_segment_index - 1;
                 point_type label_point = corner.front();
-                if (corner.size() >= 2)
+                int const mid_offset = piece.offsetted_count / 2 - 1;
+                if (mid_offset >= 0 && mid_offset + 1 < corner.size())
                 {
-                    bg::set<0>(label_point, (bg::get<0>(corner[0]) + bg::get<0>(corner[1])) / 2.0);
-                    bg::set<1>(label_point, (bg::get<1>(corner[0]) + bg::get<1>(corner[1])) / 2.0);
+                    bg::set<0>(label_point, (bg::get<0>(corner[mid_offset]) + bg::get<0>(corner[mid_offset + 1])) / 2.0);
+                    bg::set<1>(label_point, (bg::get<1>(corner[mid_offset]) + bg::get<1>(corner[mid_offset + 1])) / 2.0);
                 }
                 m_mapper.text(label_point, out.str(), "fill:rgb(255,0,0);font-family='Arial';font-size:10px;", 5, 5);
             }

From f98549f82d0278b982cbeed27dd506acc03bca17 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 15:34:33 +0200
Subject: [PATCH 12/18] [buffer][test] Minor change in comments/whitespace

---
 test/algorithms/buffer/multi_polygon_buffer.cpp | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index e6293b62f..94fdd18dc 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -24,7 +24,7 @@ static std::string const wrapped
 static std::string const triangles
     = "MULTIPOLYGON(((0 4,3 0,-2.5 -1,0 4)),((3 8,5.5 13,8 8,3 8)),((11 4,13.5 -1,8 0,11 4)))";
 
-// From robustness tests
+// From robustness tests (rt)
 
 // Case with duplicate points (due to chained boxes) (round)
 static std::string const rt_a
@@ -89,7 +89,6 @@ static std::string const rt_m1
 static std::string const rt_m2
     = "MULTIPOLYGON(((0 3,1 4,1 3,0 3)),((3 6,4 7,4 6,4 5,3 5,3 6)))";
 
-
 // Segment-intersection problem (disjoint nearly collinear segments were reported as intersecting), fixed.
 static std::string const rt_n
     = "MULTIPOLYGON(((0 0,1 1,1 0,0 0)),((3 3,4 4,4 3,3 3)))";
@@ -188,11 +187,9 @@ static std::string const rt_p20
 static std::string const rt_p21
     = "MULTIPOLYGON(((4 2,4 3,5 3,4 2)),((4 1,5 2,5 1,4 1)),((5 2,6 3,6 2,5 2)))";
 
-
 static std::string const rt_p22
     = "MULTIPOLYGON(((4 8,5 9,5 8,4 8)),((5 9,6 10,6 9,5 9)),((1 7,1 8,2 8,2 7,1 7)),((2 6,3 7,3 6,2 6)))";
 
-
 // Occupation map with a uu-turn
 static std::string const rt_q1
     = "MULTIPOLYGON(((4 6,4 7,5 7,5 6,4 6)),((1 6,1 7,2 7,2 6,1 6)),((1 9,1 10,2 10,2 9,1 9)))";

From 1830208b74822f88ec83714ce3aba2578dd9680b Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Sun, 10 Aug 2014 19:21:21 +0200
Subject: [PATCH 13/18] [buffer][test] Add rt_u7 which is currently failing
 because of tripled IP, needing get_left_turn info again. Added debug info

---
 .../buffer/multi_polygon_buffer.cpp           | 13 +++++++++++-
 test/algorithms/buffer/test_buffer.hpp        | 20 +++++++++++++++++--
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/test/algorithms/buffer/multi_polygon_buffer.cpp b/test/algorithms/buffer/multi_polygon_buffer.cpp
index 94fdd18dc..c86c75a6a 100644
--- a/test/algorithms/buffer/multi_polygon_buffer.cpp
+++ b/test/algorithms/buffer/multi_polygon_buffer.cpp
@@ -233,7 +233,10 @@ static std::string const rt_u5
 static std::string const rt_u6
     = "MULTIPOLYGON(((2 2,3 3,3 2,2 2)),((9 8,9 9,10 9,10 8,9 8)),((5 3,6 4,6 3,5 3)),((5 5,5 6,6 6,5 5)),((5 1,6 2,6 1,5 1)),((6 5,7 6,7 5,6 5)),((3 0,4 1,4 0,3 0)),((6 6,6 7,7 6,6 6)),((9 2,10 2,10 1,9 1,9 2)),((6 8,6 9,7 9,7 8,6 8)),((7 0,7 1,8 0,7 0)),((4 4,4 5,5 5,4 4)),((0 7,0 8,1 8,0 7)),((5 9,6 10,6 9,5 9)),((4 9,4 10,5 10,5 9,4 9)),((3 7,4 7,3 6,2 6,3 7)),((9 7,10 6,9 6,8 6,9 7)),((5 3,5 2,4 2,4 3,4 4,5 4,5 3)),((1 1,2 0,1 0,0 0,1 1)),((2 10,3 10,3 9,2 9,1 9,1 10,2 10)),((8.5 4.5,9 4,8 4,7 4,8 5,9 5,8.5 4.5)),((8 3,9 3,9 2,8 2,8 3)))";
 
-
+// For this case (and more), get_left_turns or using a more specific sort order is essential
+static std::string const rt_u7
+    = "MULTIPOLYGON(((4 5,4 6,5 5,4 5)),((9 2,9 3,10 3,10 2,9 2)),((7 3,7 4,8 4,8 3,7 3)),((5 5,6 6,6 5,5 5)),((3 6,4 7,4 6,3 6)),((0 5,0 6,1 5,0 5)))";
+  //  = "MULTIPOLYGON(((4 5,4 6,5 5,4 5)),((9 2,9 3,10 3,10 2,9 2)),((7 3,7 4,8 4,8 3,7 3)),((5 5,6 6,6 5,5 5)),((3 6,4 7,4 6,3 6)))"; //removing the leftmost uninvolved polygon solves somehow the problem...
 
 template <typename P>
 void test_all()
@@ -350,6 +353,12 @@ void test_all()
     test_one<multi_polygon_type, polygon_type>("rt_u4", rt_u4, join_round, end_flat, 126.9268, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u5", rt_u5, join_round, end_flat, 78.4906, 1.0);
     test_one<multi_polygon_type, polygon_type>("rt_u6", rt_u6, join_round, end_flat, 115.4461, 1.0);
+#if defined(BOOST_GEOMETRY_BUFFER_INCLUDE_FAILING_TESTS)
+    {
+        bg::strategy::buffer::join_round join_round_rough(12); // temporary
+        test_one<multi_polygon_type, polygon_type>("rt_u7", rt_u7, join_round_rough, end_flat, 999, 1.0);
+    }
+#endif
 }
 
 int test_main(int, char* [])
@@ -360,3 +369,5 @@ int test_main(int, char* [])
     return 0;
 }
 
+// intersecting:
+//= "MULTIPOLYGON(((8 6,9 7,9 6,8 6)),((0 6,0 7,1 6,0 6)),((1 6,1 7,2 7,2 6,1 6)),((2 0,2 1,3 0,2 0)),((9 2,10 3,10 2,9 2)),((7 0,7 1,8 1,7 0)),((4 6,5 7,5 6,4 6)),((7 1,7 2,8 2,7 1)),((0 8,0 9,1 8,0 8)),((0 1,0 2,1 2,0 1)),((7 2,7 3,8 3,7 2)),((9 8,9 9,10 8,9 8)),((5 2,5 3,6 3,6 2,5 2)),((1 1,1 2,2 2,2 1,1 1)),((5 3,4 2,4 3,5 4,6 5,6 6,6 7,7 7,7 6,8 6,7 5,8 4,7 4,6 4,5 3)),((3 4,2 4,2 5,2 6,3 6,3 5,4 5,3 4)),((3 7,2 7,2 8,3 8,4 8,5 8,4 7,3 7)))";
diff --git a/test/algorithms/buffer/test_buffer.hpp b/test/algorithms/buffer/test_buffer.hpp
index a7d629779..6a8b9932d 100644
--- a/test/algorithms/buffer/test_buffer.hpp
+++ b/test/algorithms/buffer/test_buffer.hpp
@@ -111,8 +111,9 @@ struct svg_visitor
 
         std::map<robust_point_type, int, bg::less<robust_point_type> > offsets;
 
+        int index = 0;
         for (typename boost::range_iterator<Turns const>::type it =
-            boost::begin(turns); it != boost::end(turns); ++it)
+            boost::begin(turns); it != boost::end(turns); ++it, index++)
         {
             char color = 'g';
             std::string fill = "fill:rgb(0,255,0);";
@@ -132,8 +133,22 @@ struct svg_visitor
 
             fill += "fill-opacity:0.7;";
             std::ostringstream out;
-            out << it->operations[0].piece_index << "/" << it->operations[1].piece_index
+            out << index
+                << " " << it->operations[0].piece_index << "/" << it->operations[1].piece_index
                 << " " << si(it->operations[0].seg_id) << "/" << si(it->operations[1].seg_id)
+
+//              If you want to see travel information
+                << std::endl
+                << " nxt " << it->operations[0].enriched.travels_to_ip_index
+                << "/" << it->operations[1].enriched.travels_to_ip_index
+                << " or " << it->operations[0].enriched.next_ip_index
+                << "/" << it->operations[1].enriched.next_ip_index
+                //<< " frac " << it->operations[0].fraction
+
+//                If you want to see robust-point coordinates (e.g. to find duplicates)
+//                << std::endl
+//                << " " << bg::get<0>(it->robust_point) << " , " << bg::get<1>(it->robust_point)
+
                 << std::endl;
             out << " " << bg::method_char(it->method)
                 << ":" << bg::operation_char(it->operations[0].operation)
@@ -143,6 +158,7 @@ struct svg_visitor
                 << (it->count_within_near_offsetted > 0 ? "n" : "")
                 << (it->count_within > 0 ? "w" : "")
                 << (it->count_on_helper > 0 ? "h" : "")
+                << (it->count_on_multi > 0 ? "m" : "")
                 ;
 
             offsets[it->get_robust_point()] += 10;

From 024b131f1ecfdcd595f6eddc30e213b10d093268 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Mon, 11 Aug 2014 12:19:33 +0200
Subject: [PATCH 14/18] [buffer] removed wrong comments

---
 .../algorithms/detail/buffer/turn_in_piece_visitor.hpp        | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
index fa08c9cd2..ce8783adf 100644
--- a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
@@ -127,8 +127,6 @@ class turn_in_piece_visitor
 
         add_point(projected, v);
 
-        // The dot-product still overflows for boost::long_long_type with
-        // these values (should not occur, TODO: fix this)
         return taxicab_distance(subject, projected);
     }
 
@@ -162,8 +160,6 @@ class turn_in_piece_visitor
     inline calculation_type
         taxicab_distance_from_offsetted(Point const& point, Piece const& piece) const
     {
-        // TODO: replace this by the code below if that is fixed for boost::long_long_type
-        // with these contents of values
         calculation_type result = 0;
         for (int i = 1; i < piece.offsetted_count; i++)
         {

From 446b4494cfee5e715fecb5d29667290938d0db02 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Mon, 11 Aug 2014 12:25:05 +0200
Subject: [PATCH 15/18] [buffer] remove taxicab distance, comparable distance
 is OK

---
 .../detail/buffer/turn_in_piece_visitor.hpp   | 84 ++++---------------
 1 file changed, 15 insertions(+), 69 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
index ce8783adf..97463cacd 100644
--- a/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/turn_in_piece_visitor.hpp
@@ -19,6 +19,9 @@
 #include <boost/geometry/algorithms/detail/overlay/get_turn_info.hpp>
 #include <boost/geometry/strategies/buffer.hpp>
 
+#include <boost/geometry/geometries/linestring.hpp>
+#include <boost/geometry/algorithms/comparable_distance.hpp>
+
 namespace boost { namespace geometry
 {
 
@@ -85,52 +88,6 @@ class turn_in_piece_visitor
         return true;
     }
 
-    template <typename Point>
-    static inline calculation_type taxicab_distance(Point const& p, Point const& q)
-    {
-        return math::abs(geometry::get<0>(p) - geometry::get<0>(q))
-             + math::abs(geometry::get<1>(p) - geometry::get<1>(q));
-    }
-
-
-    // TODO: see comment below, this adaption of distance_projected_point can be removed
-    template <typename Point>
-    static inline calculation_type taxicab_distance_from_segment(Point const& subject, Point const& p, Point const& q)
-    {
-        typedef Point vector_type;
-        typedef typename geometry::coordinate_type<Point>::type coordinate_type;
-
-        vector_type v = q;
-        vector_type w = subject;
-        subtract_point(v, p);
-        subtract_point(w, p);
-
-        coordinate_type const zero = coordinate_type();
-        coordinate_type const c1 = dot_product(w, v);
-
-        if (c1 <= zero)
-        {
-            return taxicab_distance(subject, p);
-        }
-        coordinate_type const c2 = dot_product(v, v);
-        if (c2 <= c1)
-        {
-            return taxicab_distance(subject, q);
-        }
-
-        multiply_value(v, c1);
-        divide_value(v, c2);
-
-        Point projected = p;
-        subtract_point(v, projected);
-        subtract_point(w, projected);
-
-        add_point(projected, v);
-
-        return taxicab_distance(subject, projected);
-    }
-
-
     template <typename Point, typename Piece>
     inline bool on_offsetted(Point const& point, Piece const& piece) const
     {
@@ -157,30 +114,19 @@ class turn_in_piece_visitor
     }
 
     template <typename Point, typename Piece>
-    inline calculation_type
-        taxicab_distance_from_offsetted(Point const& point, Piece const& piece) const
+    static inline
+    calculation_type comparable_distance_from_offsetted(Point const& point,
+                        Piece const& piece)
     {
-        calculation_type result = 0;
-        for (int i = 1; i < piece.offsetted_count; i++)
-        {
-            Point const& previous = piece.robust_ring[i - 1];
-            Point const& current = piece.robust_ring[i];
-            calculation_type const dist
-                    = taxicab_distance_from_segment(point, previous, current);
-            if (i == 1 || dist < result)
-            {
-                result = dist;
-            }
-        }
-        return result;
-
-        /*
+        // TODO: pass subrange to dispatch to avoid making copy
         geometry::model::linestring<Point> ls;
-        std::copy(piece.robust_ring.begin(), piece.robust_ring.begin() + piece.offsetted_count, std::back_inserter(ls));
+        std::copy(piece.robust_ring.begin(),
+            piece.robust_ring.begin() + piece.offsetted_count,
+            std::back_inserter(ls));
         typename default_comparable_distance_result<Point, Point>::type
-            const result = geometry::comparable_distance(point, ls);
-        return result;
-        */
+            const comp = geometry::comparable_distance(point, ls);
+
+        return static_cast<calculation_type>(comp);
     }
 
 public:
@@ -267,8 +213,8 @@ public:
         if (geometry_code == 1)
         {
             calculation_type const distance
-                = taxicab_distance_from_offsetted(turn.robust_point, piece);
-            if (distance >= 2)
+                = comparable_distance_from_offsetted(turn.robust_point, piece);
+            if (distance >= 4)
             {
                 // This is too far from the border, it counts as "really within"
                 mutable_turn.count_within++;

From c42aeb44472b76d849c792d0b8922e406ab83210 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Wed, 27 Aug 2014 12:27:57 +0200
Subject: [PATCH 16/18] [buffer][fix] fix neighbour check in calculating turns.
 This fixes ticket 10398

---
 .../detail/buffer/get_piece_turns.hpp         | 11 ++------
 test/algorithms/buffer/polygon_buffer.cpp     | 27 +++++++++----------
 2 files changed, 14 insertions(+), 24 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp b/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp
index e3c41a2a4..b2b974806 100644
--- a/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp
@@ -56,7 +56,6 @@ class piece_turn_visitor
     Rings const& m_rings;
     Turns& m_turns;
     RobustPolicy const& m_robust_policy;
-    int m_last_piece_index;
 
     template <typename Piece>
     inline bool is_adjacent(Piece const& piece1, Piece const& piece2) const
@@ -66,14 +65,8 @@ class piece_turn_visitor
             return false;
         }
 
-        if (std::abs(piece1.index - piece2.index) == 1)
-        {
-            return true;
-        }
-
-        return (piece1.index == 0 && piece2.index == m_last_piece_index)
-            || (piece1.index == m_last_piece_index && piece2.index == 0)
-            ;
+        return piece1.index == piece2.left_index
+            || piece1.index == piece2.right_index;
     }
 
     template <typename Range, typename Iterator>
diff --git a/test/algorithms/buffer/polygon_buffer.cpp b/test/algorithms/buffer/polygon_buffer.cpp
index 173c4316b..514a019ca 100644
--- a/test/algorithms/buffer/polygon_buffer.cpp
+++ b/test/algorithms/buffer/polygon_buffer.cpp
@@ -324,24 +324,21 @@ void test_all()
     test_one<polygon_type, polygon_type>("donut_simplex6", donut_simplex, join_miter, end_flat, 12.8920, -0.6);
     test_one<polygon_type, polygon_type>("donut_simplex6", donut_simplex, join_round, end_flat, 12.9157, -0.6);
 
-#if defined(BOOST_GEOMETRY_BUFFER_INCLUDE_FAILING_TESTS)
-    // Areas yet to be changed
-    test_one<polygon_type, polygon_type>("ticket_10398_1_5", ticket_10398_1, join_miter, end_flat, 99, 0.5);
-    test_one<polygon_type, polygon_type>("ticket_10398_1_25", ticket_10398_1, join_miter, end_flat, 99, 2.5);
-    test_one<polygon_type, polygon_type>("ticket_10398_1_84", ticket_10398_1, join_miter, end_flat, 99, 8.4);
+    test_one<polygon_type, polygon_type>("ticket_10398_1_5", ticket_10398_1, join_miter, end_flat, 494.7192, 0.5, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_1_25", ticket_10398_1, join_miter, end_flat, 697.7798, 2.5, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_1_84", ticket_10398_1, join_miter, end_flat, 1470.8096, 8.4, -999, false);
 
-    test_one<polygon_type, polygon_type>("ticket_10398_2_45", ticket_10398_2, join_miter, end_flat, 99, 4.5);
-    test_one<polygon_type, polygon_type>("ticket_10398_2_62", ticket_10398_2, join_miter, end_flat, 99, 6.2);
-    test_one<polygon_type, polygon_type>("ticket_10398_2_73", ticket_10398_2, join_miter, end_flat, 99, 7.3);
+    test_one<polygon_type, polygon_type>("ticket_10398_2_45", ticket_10398_2, join_miter, end_flat, 535.4780, 4.5, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_2_62", ticket_10398_2, join_miter, end_flat, 705.2046, 6.2, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_2_73", ticket_10398_2, join_miter, end_flat, 827.3394, 7.3, -999, false);
 
-    test_one<polygon_type, polygon_type>("ticket_10398_3_12", ticket_10398_3, join_miter, end_flat, 99, 1.2);
-    test_one<polygon_type, polygon_type>("ticket_10398_3_35", ticket_10398_3, join_miter, end_flat, 99, 3.5);
-    test_one<polygon_type, polygon_type>("ticket_10398_3_54", ticket_10398_3, join_miter, end_flat, 99, 5.4);
+    test_one<polygon_type, polygon_type>("ticket_10398_3_12", ticket_10398_3, join_miter, end_flat, 122.9443, 1.2, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_3_35", ticket_10398_3, join_miter, end_flat, 258.2729, 3.5, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_3_54", ticket_10398_3, join_miter, end_flat, 402.0571, 5.4, -999, false);
 
-    test_one<polygon_type, polygon_type>("ticket_10398_4_30", ticket_10398_4, join_miter, end_flat, 99, 3.0);
-    test_one<polygon_type, polygon_type>("ticket_10398_4_66", ticket_10398_4, join_miter, end_flat, 99, 6.6);
-    test_one<polygon_type, polygon_type>("ticket_10398_4_91", ticket_10398_4, join_miter, end_flat, 99, 9.1);
-#endif
+    test_one<polygon_type, polygon_type>("ticket_10398_4_30", ticket_10398_4, join_miter, end_flat, 257.9482, 3.0, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_4_66", ticket_10398_4, join_miter, end_flat, 553.0112, 6.6, -999, false);
+    test_one<polygon_type, polygon_type>("ticket_10398_4_91", ticket_10398_4, join_miter, end_flat, 819.1406, 9.1, -999, false);
 }
 
 

From 02ae40805c55c43835adea70ae666f6dcd5e1cf4 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Wed, 27 Aug 2014 12:28:44 +0200
Subject: [PATCH 17/18] [buffer] remove now redundant member m_last_piece_index

---
 .../algorithms/detail/buffer/buffered_piece_collection.hpp    | 2 +-
 .../geometry/algorithms/detail/buffer/get_piece_turns.hpp     | 4 +---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
index 1c082ac98..97a20ebe2 100644
--- a/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/buffered_piece_collection.hpp
@@ -529,7 +529,7 @@ struct buffered_piece_collection
                     buffered_ring_collection<buffered_ring<Ring> >,
                     turn_vector_type,
                     RobustPolicy
-                > visitor(offsetted_rings, m_turns, m_robust_policy, m_pieces.size());
+                > visitor(offsetted_rings, m_turns, m_robust_policy);
 
             geometry::partition
                 <
diff --git a/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp b/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp
index b2b974806..23b09e1c8 100644
--- a/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp
+++ b/include/boost/geometry/algorithms/detail/buffer/get_piece_turns.hpp
@@ -164,12 +164,10 @@ public:
 
     piece_turn_visitor(Rings const& ring_collection,
             Turns& turns,
-            RobustPolicy const& robust_policy,
-            int last_piece_index)
+            RobustPolicy const& robust_policy)
         : m_rings(ring_collection)
         , m_turns(turns)
         , m_robust_policy(robust_policy)
-        , m_last_piece_index(last_piece_index)
     {}
 
     template <typename Piece>

From 14c31c31f09ea337c9c4130a50a66670e5465d42 Mon Sep 17 00:00:00 2001
From: Barend Gehrels <barend@xs4all.nl>
Date: Wed, 27 Aug 2014 12:33:48 +0200
Subject: [PATCH 18/18] [doc] add fixed ticket to release notes

---
 doc/release_notes.qbk | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/doc/release_notes.qbk b/doc/release_notes.qbk
index 19f9187c4..40f4939be 100644
--- a/doc/release_notes.qbk
+++ b/doc/release_notes.qbk
@@ -23,6 +23,8 @@
 
 [*Solved tickets]
 
+* [@https://svn.boost.org/trac/boost/ticket/10398 10398] Wrong neighbour check in buffer, calculating turns
+
 [*Bugfixes]
 
 [/=================]