From 423596a6557491bc482e518a596c608276a58736 Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Tue, 29 Sep 2015 15:40:39 -0700
Subject: [PATCH] Port fix for https://github.com/mapbox/earcut/issues/29

Refs https://github.com/mapbox/earcut.hpp/issues/6
---
 include/earcut.hpp           |  3 ++-
 test/fixtures/geometries.hpp |  1 +
 test/fixtures/issue29.cpp    | 12 ++++++++++++
 test/test.cpp                |  1 +
 4 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 test/fixtures/issue29.cpp

diff --git a/include/earcut.hpp b/include/earcut.hpp
index a5300d6..aeafe95 100644
--- a/include/earcut.hpp
+++ b/include/earcut.hpp
@@ -683,7 +683,8 @@ Earcut<Coord, N>::getLeftmost(Node* start) {
 // check if a diagonal between two polygon nodes is valid (lies in polygon interior)
 template <typename Coord, typename N>
 bool Earcut<Coord, N>::isValidDiagonal(Node* a, Node* b) {
-    return !intersectsPolygon(a, a, b) &&
+    return a->next->i != b->i && a->prev->i != b->i &&
+           !intersectsPolygon(a, a, b) &&
            locallyInside(a, b) && locallyInside(b, a) &&
            middleInside(a, a->v, b->v);
 }
diff --git a/test/fixtures/geometries.hpp b/test/fixtures/geometries.hpp
index a15d760..3e6a9e4 100644
--- a/test/fixtures/geometries.hpp
+++ b/test/fixtures/geometries.hpp
@@ -31,6 +31,7 @@ extern const DoublePolygon dude;
 extern const IntegerPolygon empty_square;
 extern const DoublePolygon issue16;
 extern const DoublePolygon issue17;
+extern const DoublePolygon issue29;
 extern const IntegerPolygon water_huge;
 extern const IntegerPolygon water_huge2;
 extern const IntegerPolygon water;
diff --git a/test/fixtures/issue29.cpp b/test/fixtures/issue29.cpp
new file mode 100644
index 0000000..f5346e8
--- /dev/null
+++ b/test/fixtures/issue29.cpp
@@ -0,0 +1,12 @@
+#include "geometries.hpp"
+
+namespace mapbox {
+namespace fixtures {
+
+const DoublePolygon issue29 = {
+    {{200.95000055654114,69.90565782485673},{201.73186418809928,76.50881049432792},{204.05247248713854,82.73234962527638},{207.79442497901618,88.23839184455574},{212.7323883100471,92.70045673093409},{218.58296075442922,95.86217257360113},{225.00460918453172,97.53918036725955},{231.66534446463922,97.66082593216561},{238.15796607054654,96.21973398409901},{244.1176358256489,93.27806596420706},{249.2188404462824,88.99822680730722},{253.15628113771672,83.64108043884043},{255.70631344406866,77.51111824424007},{256.73126424155197,70.93641692795792},{256.19351709797047,64.30797780468129},{254.1057433114911,57.996416078653425},{250.56431880965246,52.346517799043795},{245.8112865351897,47.719993951247304},{240.07834375849924,44.33761266223155},{233.71343464441597,42.419284673407674},{227.06488359675492,42.055728640102465},{220.51757991796475,43.257153422775446},{214.45449861431845,45.97523169373744},{209.20995664413203,50.053084840223896},{205.06721924245355,55.271000209450726},{202.29122001552022,61.30178454495035},{201.02451470680535,67.8368895214051}},
+    {{242.34999892718187,69.90549289577612},{240.7584948063828,76.30057721128688},{236.31611852571368,81.17358751371503},{230.07699953842675,83.34595728587593},{223.55761859836056,82.33733346881347},{218.2910646148026,78.34856240227819},{215.5668820463121,72.34290095195175},{215.9904494531453,65.75019118711353},{219.47497291108593,60.1536534355022},{225.2189893186092,56.88651757836341},{231.8100271829404,56.72041164720431},{237.70269737243652,59.67713584899902},{241.47838292121884,65.0856644153595}},
+};
+
+}
+}
diff --git a/test/test.cpp b/test/test.cpp
index ead4eff..4880f23 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -121,6 +121,7 @@ int main() {
     areaTest<int>("water4", mapbox::fixtures::water4);
     areaTest<int>("issue16", mapbox::fixtures::issue16);
     areaTest<int>("issue17", mapbox::fixtures::issue17);
+    areaTest<int>("issue29", mapbox::fixtures::issue29);
     areaTest<short>("park", mapbox::fixtures::park);
     areaTest<int>("issue34", mapbox::fixtures::issue34);