From 5e68959c03cc460edd93d7dbe9444d8250958711 Mon Sep 17 00:00:00 2001
From: j433866 <j433866@gmail.com>
Date: Tue, 15 Jan 2019 10:25:49 +0000
Subject: [PATCH] Catch when OS grid references aren't calculated

---
 src/core/lib/ConvertCoordinates.mjs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/core/lib/ConvertCoordinates.mjs b/src/core/lib/ConvertCoordinates.mjs
index 06e40f02..b6f9e9bf 100644
--- a/src/core/lib/ConvertCoordinates.mjs
+++ b/src/core/lib/ConvertCoordinates.mjs
@@ -81,6 +81,9 @@ export function convertCoordinates (inLat, inLong, inFormat, outFormat, precisio
         const latlon = new geodesy.LatLonEllipsoidal(parseFloat(convLat), parseFloat(convLong));
         const osng = geodesy.OsGridRef.latLonToOsGrid(latlon);
         convLat = osng.toString();
+        if (convLat === "") {
+            throw "Couldn't convert co-ordinates to Ordnance Survey National Grid. Are they out of range?";
+        }
     } else {
         convLat = convertSingleCoordinate(convLat.toString(), "Decimal Degrees", outFormat, precision);
         convLong = convertSingleCoordinate(convLong.toString(), "Decimal Degrees", outFormat, precision);