From a4825f6af485e56ef1819a290b34dada4373f52d Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Tue, 15 May 2018 12:55:17 -0700
Subject: [PATCH] Explicitly check for infinite and not-a-number input
 coordinates

---
 CHANGELOG.md   |  4 ++++
 projection.cpp | 24 ++++++++++++++++++++++++
 version.hpp    |  2 +-
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80e019d..32c0adb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.28.1
+
+* Explicitly check for infinite and not-a-number input coordinates
+
 ## 1.28.0
 
 * Directly support gzipped GeoJSON as input files
diff --git a/projection.cpp b/projection.cpp
index ae293da..2b63777 100644
--- a/projection.cpp
+++ b/projection.cpp
@@ -14,6 +14,18 @@ struct projection *projection = &projections[0];
 
 // http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
 void lonlat2tile(double lon, double lat, int zoom, long long *x, long long *y) {
+	// Place infinite and NaN coordinates off the edge of the Mercator plane
+
+	int lat_class = fpclassify(lat);
+	int lon_class = fpclassify(lon);
+
+	if (lat_class == FP_INFINITE || lat_class == FP_NAN) {
+		lat = 89.9;
+	}
+	if (lon_class == FP_INFINITE || lon_class == FP_NAN) {
+		lon = 360;
+	}
+
 	// Must limit latitude somewhere to prevent overflow.
 	// 89.9 degrees latitude is 0.621 worlds beyond the edge of the flat earth,
 	// hopefully far enough out that there are few expectations about the shape.
@@ -49,6 +61,18 @@ void tile2lonlat(long long x, long long y, int zoom, double *lon, double *lat) {
 }
 
 void epsg3857totile(double ix, double iy, int zoom, long long *x, long long *y) {
+	// Place infinite and NaN coordinates off the edge of the Mercator plane
+
+	int iy_class = fpclassify(iy);
+	int ix_class = fpclassify(ix);
+
+	if (iy_class == FP_INFINITE || iy_class == FP_NAN) {
+		iy = 40000000.0;
+	}
+	if (ix_class == FP_INFINITE || ix_class == FP_NAN) {
+		ix = 40000000.0;
+	}
+
 	*x = ix * (1LL << 31) / 6378137.0 / M_PI + (1LL << 31);
 	*y = ((1LL << 32) - 1) - (iy * (1LL << 31) / 6378137.0 / M_PI + (1LL << 31));
 
diff --git a/version.hpp b/version.hpp
index 3276f8f..465ccfc 100644
--- a/version.hpp
+++ b/version.hpp
@@ -1,6 +1,6 @@
 #ifndef VERSION_HPP
 #define VERSION_HPP
 
-#define VERSION "tippecanoe v1.28.0\n"
+#define VERSION "tippecanoe v1.28.1\n"
 
 #endif