From e1aa283fc9a596d479bfe0faa3ea784f6da554d0 Mon Sep 17 00:00:00 2001
From: Paul Kaplan <pkaplan@media.mit.edu>
Date: Tue, 19 Jun 2018 15:43:46 -0400
Subject: [PATCH] Do not call onDrop if newIndex is null

---
 src/lib/sortable-hoc.jsx | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/lib/sortable-hoc.jsx b/src/lib/sortable-hoc.jsx
index 665c5bc43..76d862447 100644
--- a/src/lib/sortable-hoc.jsx
+++ b/src/lib/sortable-hoc.jsx
@@ -26,8 +26,10 @@ const SortableHOC = function (WrappedComponent) {
                     return a.top - b.top;
                 });
             } else if (!newProps.dragInfo.dragging && this.props.dragInfo.dragging) {
-                this.props.onDrop(Object.assign({},
-                    this.props.dragInfo, {newIndex: this.getMouseOverIndex()}));
+                const newIndex = this.getMouseOverIndex();
+                if (newIndex !== null) {
+                    this.props.onDrop(Object.assign({}, this.props.dragInfo, {newIndex}));
+                }
             }
         }