From 23c7afc8a57ed9d25a2f250a52dc89d956967015 Mon Sep 17 00:00:00 2001
From: Robert Paskowitz <rpaskowitz@users.noreply.github.com>
Date: Wed, 12 Apr 2017 15:03:11 -0400
Subject: [PATCH] Passthrough the wheel event if the scrollbar is at the very
 top or bottom of the box.

---
 src/components/legend/draw.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/components/legend/draw.js b/src/components/legend/draw.js
index beb5f58a1c8..93b736fd33e 100644
--- a/src/components/legend/draw.js
+++ b/src/components/legend/draw.js
@@ -269,7 +269,9 @@ module.exports = function draw(gd) {
             scrollBarY = constants.scrollBarMargin -
                 scrollBoxY / scrollBoxYMax * scrollBarYMax;
             scrollHandler(scrollBarY, scrollBoxY);
-            d3.event.preventDefault();
+            if(scrollBoxY !== 0 && scrollBoxY !== -scrollBoxYMax) {
+                d3.event.preventDefault();
+            }
         });
 
         // to be safe, remove previous listeners