From 1d0a239ec5d581c3f7637a6833d1e88a9766ae1f Mon Sep 17 00:00:00 2001
From: Tim Dettrick <t.dettrick@uq.edu.au>
Date: Wed, 2 Aug 2017 17:10:23 +1000
Subject: [PATCH] Fix bbox-clip point intersection handling

Ensure a polygon that has a single point touching the bounding box will
be handled without an error.
---
 packages/turf-bbox-clip/index.js              |   4 +-
 .../in/polygon-point-intersection.geojson     |  83 ++++++++++++++
 .../out/polygon-point-intersection.geojson    | 106 ++++++++++++++++++
 3 files changed, 192 insertions(+), 1 deletion(-)
 create mode 100644 packages/turf-bbox-clip/test/in/polygon-point-intersection.geojson
 create mode 100644 packages/turf-bbox-clip/test/out/polygon-point-intersection.geojson

diff --git a/packages/turf-bbox-clip/index.js b/packages/turf-bbox-clip/index.js
index a4b5898bc7..b63136f310 100644
--- a/packages/turf-bbox-clip/index.js
+++ b/packages/turf-bbox-clip/index.js
@@ -57,7 +57,9 @@ function clipPolygon(rings, bbox) {
             if (clipped[0][0] !== clipped[clipped.length - 1][0] || clipped[0][1] !== clipped[clipped.length - 1][1]) {
                 clipped.push(clipped[0]);
             }
-            outRings.push(clipped);
+            if (clipped.length >= 4) {
+                outRings.push(clipped);
+            }
         }
     }
     return outRings;
diff --git a/packages/turf-bbox-clip/test/in/polygon-point-intersection.geojson b/packages/turf-bbox-clip/test/in/polygon-point-intersection.geojson
new file mode 100644
index 0000000000..0b5002a451
--- /dev/null
+++ b/packages/turf-bbox-clip/test/in/polygon-point-intersection.geojson
@@ -0,0 +1,83 @@
+{
+  "type": "FeatureCollection",
+  "features": [
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "type": "Polygon",
+        "coordinates": [
+          [
+            [
+              115.872872384,
+              -31.977789227500004
+            ],
+            [
+              115.87413347200001,
+              -31.978896027
+            ],
+            [
+              115.874207392,
+              -31.978955634
+            ],
+            [
+              115.874293312,
+              -31.978886666
+            ],
+            [
+              115.875,
+              -31.9782948325
+            ],
+            [
+              115.873511744,
+              -31.977027638
+            ],
+            [
+              115.8731464,
+              -31.977071372
+            ],
+            [
+              115.872185504,
+              -31.9771863865
+            ],
+            [
+              115.872872384,
+              -31.977789227500004
+            ]
+          ]
+        ]
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {},
+      "geometry": {
+        "type": "Polygon",
+        "coordinates": [
+          [
+            [
+              115.875,
+              -31.98
+            ],
+            [
+              115.880,
+              -31.98
+            ],
+            [
+              115.880,
+              -31.975
+            ],
+            [
+              115.875,
+              -31.975
+            ],
+            [
+              115.875,
+              -31.98
+            ]
+          ]
+        ]
+      }
+    }
+  ]
+}
diff --git a/packages/turf-bbox-clip/test/out/polygon-point-intersection.geojson b/packages/turf-bbox-clip/test/out/polygon-point-intersection.geojson
new file mode 100644
index 0000000000..d9fb5742d3
--- /dev/null
+++ b/packages/turf-bbox-clip/test/out/polygon-point-intersection.geojson
@@ -0,0 +1,106 @@
+{
+  "type": "FeatureCollection",
+  "features": [
+    {
+      "type": "Feature",
+      "properties": {
+        "stroke": "#080",
+        "fill": "#080",
+        "stroke-width": 6,
+        "fill-opacity": 0.1
+      },
+      "geometry": {
+        "type": "Polygon",
+        "coordinates": [
+          [
+            [
+              115.872872384,
+              -31.977789227500004
+            ],
+            [
+              115.87413347200001,
+              -31.978896027
+            ],
+            [
+              115.874207392,
+              -31.978955634
+            ],
+            [
+              115.874293312,
+              -31.978886666
+            ],
+            [
+              115.875,
+              -31.9782948325
+            ],
+            [
+              115.873511744,
+              -31.977027638
+            ],
+            [
+              115.8731464,
+              -31.977071372
+            ],
+            [
+              115.872185504,
+              -31.9771863865
+            ],
+            [
+              115.872872384,
+              -31.977789227500004
+            ]
+          ]
+        ]
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {
+        "stroke": "#F00",
+        "fill": "#F00",
+        "stroke-width": 6,
+        "fill-opacity": 0.1
+      },
+      "geometry": {
+        "type": "Polygon",
+        "coordinates": []
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": {
+        "stroke": "#00F",
+        "fill": "#00F",
+        "stroke-width": 3,
+        "fill-opacity": 0.1
+      },
+      "geometry": {
+        "type": "Polygon",
+        "coordinates": [
+          [
+            [
+              115.875,
+              -31.98
+            ],
+            [
+              115.880,
+              -31.98
+            ],
+            [
+              115.880,
+              -31.975
+            ],
+            [
+              115.875,
+              -31.975
+            ],
+            [
+              115.875,
+              -31.98
+            ]
+          ]
+        ]
+      }
+    }
+  ]
+}