From 4a6e354497f93d3b4005ed732015fccd62a61440 Mon Sep 17 00:00:00 2001
From: Oscar Kilhed <oscar.kilhed@grafana.com>
Date: Thu, 23 Sep 2021 10:40:44 +0200
Subject: [PATCH] PieChart: Fix sorting for null values in piechart (#39516)

* Fix sorting for null values in piechart

Co-authored-by: Ashley Harrison <ashley.harrison@grafana.com>
---
 public/app/plugins/panel/piechart/PieChartPanel.tsx | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/public/app/plugins/panel/piechart/PieChartPanel.tsx b/public/app/plugins/panel/piechart/PieChartPanel.tsx
index 236b31f6cd7..8e93d529262 100644
--- a/public/app/plugins/panel/piechart/PieChartPanel.tsx
+++ b/public/app/plugins/panel/piechart/PieChartPanel.tsx
@@ -87,7 +87,15 @@ function getLegend(props: Props, displayValues: FieldDisplay[]) {
 
   const legendItems = displayValues
     // Since the pie chart is always sorted, let's sort the legend as well.
-    .sort((a, b) => b.display.numeric - a.display.numeric)
+    .sort((a, b) => {
+      if (isNaN(a.display.numeric)) {
+        return 1;
+      } else if (isNaN(b.display.numeric)) {
+        return -1;
+      } else {
+        return b.display.numeric - a.display.numeric;
+      }
+    })
     .map<VizLegendItem>((value, idx) => {
       const hidden = value.field.custom.hideFrom.viz;
       const display = value.display;