From 2df32acb05d3929d1c56cea1d11a2b67b00d79c5 Mon Sep 17 00:00:00 2001
From: Grace Guo <grace.guo@airbnb.com>
Date: Thu, 1 Mar 2018 14:15:25 -0800
Subject: [PATCH] [dashboard]

---
 superset/assets/javascripts/dashboard/reducers.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/superset/assets/javascripts/dashboard/reducers.js b/superset/assets/javascripts/dashboard/reducers.js
index 80137c5af008f..bf42532edb51a 100644
--- a/superset/assets/javascripts/dashboard/reducers.js
+++ b/superset/assets/javascripts/dashboard/reducers.js
@@ -41,8 +41,9 @@ export function getInitialState(bootstrapData) {
   } else {
     dashboard.position_json = [];
   }
-  const lastRowId = Math.max.apply(null,
-    dashboard.position_json.map(pos => (pos.row + pos.size_y)));
+
+  const lastRowId = Math.max(0, Math.max.apply(null,
+    dashboard.position_json.map(pos => (pos.row + pos.size_y))));
   let newSliceCounter = 0;
   dashboard.slices.forEach((slice) => {
     const sliceId = slice.slice_id;