From b445dc832e4bc92d8198a6e3b23d600f41518a26 Mon Sep 17 00:00:00 2001
From: platinops <platinops@gmail.com>
Date: Tue, 24 Feb 2026 14:14:22 +0100
Subject: [PATCH] Prevent NaN lonShift from crashing hover

---
 src/traces/scattermap/hover.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/traces/scattermap/hover.js b/src/traces/scattermap/hover.js
index af476fd6778..b1865ed1b93 100644
--- a/src/traces/scattermap/hover.js
+++ b/src/traces/scattermap/hover.js
@@ -26,6 +26,8 @@ function hoverPoints(pointData, xval, yval) {
     var winding = (xval >= 0) ?
         Math.floor((xval + 180) / 360) :
         Math.ceil((xval - 180) / 360);
+    // if xval is undefined, so will be winding
+    if(isNaN(winding)) winding = 0;
 
     // shift longitude to [-180, 180] to determine closest point
     var lonShift = winding * 360;