From df434ad2f6caef703347b1eaea7b4b58cbccda66 Mon Sep 17 00:00:00 2001
From: Dmitry Taimanov <taimanov@haulmont.com>
Date: Wed, 10 Jun 2020 18:58:41 +0400
Subject: [PATCH] IndexOutOfBoundsException when run diagram report with empty
 data #258

---
 .../reports/entity/charts/ChartToJsonConverter.java   | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/modules/global/src/com/haulmont/reports/entity/charts/ChartToJsonConverter.java b/modules/global/src/com/haulmont/reports/entity/charts/ChartToJsonConverter.java
index facaf52b..d2ca0fd5 100644
--- a/modules/global/src/com/haulmont/reports/entity/charts/ChartToJsonConverter.java
+++ b/modules/global/src/com/haulmont/reports/entity/charts/ChartToJsonConverter.java
@@ -128,11 +128,7 @@ public String convertSerialChart(SerialChartDescription description, List<Map<St
             graphs.add(graph);
         }
 
-        Optional.ofNullable(data.get(0)).ifPresent(map -> {
-            if (map instanceof EntityMap) {
-                sortByCategoryField(data, description.getCategoryField());
-            }
-        });
+        sortByCategoryFieldIfNeed(data, description.getCategoryField());
 
         JsonElement jsonTree = gson.toJsonTree(chart);
         jsonTree.getAsJsonObject().add("dataProvider", serializeData(data, fields));
@@ -145,7 +141,10 @@ public String convertSerialChart(SerialChartDescription description, List<Map<St
         return gson.toJson(jsonTree);
     }
 
-    private void sortByCategoryField(List<Map<String, Object>> data, String categoryField) {
+    private void sortByCategoryFieldIfNeed(List<Map<String, Object>> data, String categoryField) {
+        if (data.isEmpty() || !(data.get(0) instanceof EntityMap))
+            return;
+
         data.sort((entityMap1, entityMap2) -> {
             int compareResult;