From b2683f48f23a9db0a577ca52b6c7edeeb4c8c0a2 Mon Sep 17 00:00:00 2001
From: Menelaos Karavelas <menelaos.karavelas@gmail.com>
Date: Tue, 4 Nov 2014 22:02:47 +0200
Subject: [PATCH 1/2] [strategies][cartesian][cart_intersect] fix bug in
 Cartesian segment-segment intersection strategy; Bug: when exactly one
 segment degenerates to a point and is collinear with the other segment, the
 strategy always sets the intersection count to 1; Fix: check if the
 degenerate segment lies within the non-degenerate one before setting the
 intersection count; if the point is outside the non-degenerate segment
 declare the two segments as disjoint;

---
 .../boost/geometry/strategies/cartesian/cart_intersect.hpp  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/boost/geometry/strategies/cartesian/cart_intersect.hpp b/include/boost/geometry/strategies/cartesian/cart_intersect.hpp
index 66af2d2e9..8f2c53e2a 100644
--- a/include/boost/geometry/strategies/cartesian/cart_intersect.hpp
+++ b/include/boost/geometry/strategies/cartesian/cart_intersect.hpp
@@ -351,6 +351,12 @@ private:
         //              b1/b2      (4..4)
         // Ratio: (4-2)/(6-2)
         RatioType const ratio(d - s1, s2 - s1);
+
+        if (!ratio.on_segment())
+        {
+            return Policy::disjoint();
+        }
+
         return Policy::one_degenerate(degenerate_segment, ratio, a_degenerate);
     }
 };

From 1b638c66fc9b833296db4839bc11669956b82664 Mon Sep 17 00:00:00 2001
From: Menelaos Karavelas <menelaos.karavelas@gmail.com>
Date: Tue, 4 Nov 2014 22:06:18 +0200
Subject: [PATCH 2/2] [test][distance] add some more P/L and L/L test cases;
 some of them have triggered the bug in the Cartesian segment-segment
 intersection strategy and the distance has produced wrong results; with the
 fix in the Cartesian segment-segment intersection strategy, the distance
 computation test cases added succeed;

---
 .../distance/distance_linear_linear.cpp          | 16 ++++++++++++++++
 .../distance/distance_pointlike_linear.cpp       | 15 +++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/test/algorithms/distance/distance_linear_linear.cpp b/test/algorithms/distance/distance_linear_linear.cpp
index 9c329e429..72c75805d 100644
--- a/test/algorithms/distance/distance_linear_linear.cpp
+++ b/test/algorithms/distance/distance_linear_linear.cpp
@@ -75,6 +75,10 @@ void test_distance_segment_linestring(Strategy const& strategy)
     tester::apply("segment(1 1,2 2)",
                   "linestring(2 1,1 2,4 0)",
                   0, 0, strategy);
+
+    tester::apply("segment(1 1,2 2)",
+                  "linestring(3 3,3 3)",
+                  sqrt(2.0), 2, strategy);
 }
 
 //===========================================================================
@@ -155,6 +159,10 @@ void test_distance_segment_multilinestring(Strategy const& strategy)
     tester::apply("segment(1 1,2 2)",
                   "multilinestring((2 1,1 2),(4 0,4 10))",
                   0, 0, strategy);
+
+    tester::apply("segment(1 1,2 2)",
+                  "multilinestring((2.5 0,4 0,5 0),(3 3,3 3))",
+                   sqrt(2.0), 2, strategy);
 }
 
 //===========================================================================
@@ -179,6 +187,14 @@ void test_distance_linestring_multilinestring(Strategy const& strategy)
     tester::apply("linestring(1 1,2 2,3 3)",
                   "multilinestring((1 -10,2 0,2.1 -10,4 0),(1 -10,2 1.9,2.1 -10,4 0))",
                   sqrt(0.005), 0.005, strategy, true);
+
+    tester::apply("linestring(1 1,2 2)",
+                  "multilinestring((2.5 0,4 0,5 0),(3 3,3 3))",
+                   sqrt(2.0), 2, strategy);
+
+    tester::apply("linestring(1 1,2 2,3 3,4 4,5 5,6 6,7 7,8 8,9 9)",
+                  "multilinestring((2.5 0,4 0,5 0),(10 10,10 10))",
+                   sqrt(2.0), 2, strategy);
 }
 
 //===========================================================================
diff --git a/test/algorithms/distance/distance_pointlike_linear.cpp b/test/algorithms/distance/distance_pointlike_linear.cpp
index cc5fce764..742554259 100644
--- a/test/algorithms/distance/distance_pointlike_linear.cpp
+++ b/test/algorithms/distance/distance_pointlike_linear.cpp
@@ -99,6 +99,18 @@ void test_distance_point_multilinestring(Strategy const& strategy)
     tester::apply("point(2.5 0)",
                   "multilinestring((-5 0,-3 0),(2 0,3 0))",
                   0, 0, strategy);
+    tester::apply("POINT(0 0)",
+                  "MULTILINESTRING((10 10,10 0),(0.0 -0.0,0.0 -0.0))",
+                  0, 0, strategy);
+    tester::apply("POINT(0 0)",
+                  "MULTILINESTRING((10 10,10 0),(1 1,1 1))",
+                  sqrt(2.0), 2, strategy);
+    tester::apply("POINT(0 0)",
+                  "MULTILINESTRING((10 10,10 0),(1 1,2 2))",
+                  sqrt(2.0), 2, strategy);
+    tester::apply("POINT(0 0)",
+                  "MULTILINESTRING((10 10,10 0),(20 20,20 20))",
+                  10, 100, strategy);
 }
 
 //===========================================================================
@@ -180,6 +192,9 @@ void test_distance_multipoint_segment(Strategy const& strategy)
     tester::apply("multipoint(0 0,1 0,0 1,1 1)",
                   "segment(3 3,4 4)",
                   sqrt(8.0), 8, strategy);
+    tester::apply("multipoint(4 4,5 5,2 2,3 3)",
+                  "segment(0 0,1 1)",
+                  sqrt(2.0), 2, strategy);
 }
 
 //===========================================================================