From e95a4d84d094763f706ff7e5585a5374b1638013 Mon Sep 17 00:00:00 2001
From: PJ Fanning <fanningpj@apache.org>
Date: Wed, 8 Nov 2023 12:34:41 +0000
Subject: [PATCH] [bug-67510] issue with empty num format on chart axes

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1913674 13f79535-47bb-0310-9956-ffa450edef68
---
 .../apache/poi/xddf/usermodel/chart/XDDFChartAxis.java   | 4 ++--
 .../poi/xssf/usermodel/charts/TestXSSFChartAxis.java     | 9 ++++-----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/poi-ooxml/src/main/java/org/apache/poi/xddf/usermodel/chart/XDDFChartAxis.java b/poi-ooxml/src/main/java/org/apache/poi/xddf/usermodel/chart/XDDFChartAxis.java
index b565987f84..cac2864a4f 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/xddf/usermodel/chart/XDDFChartAxis.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/xddf/usermodel/chart/XDDFChartAxis.java
@@ -146,10 +146,10 @@ public abstract class XDDFChartAxis implements HasShapeProperties {
     }
 
     /**
-     * @return axis number format
+     * @return axis number format (can be null if no number format is set)
      */
     public String getNumberFormat() {
-        return getCTNumFmt().getFormatCode();
+        return hasNumberFormat() ? getCTNumFmt().getFormatCode() : null;
     }
 
     /**
diff --git a/poi-ooxml/src/test/java/org/apache/poi/xssf/usermodel/charts/TestXSSFChartAxis.java b/poi-ooxml/src/test/java/org/apache/poi/xssf/usermodel/charts/TestXSSFChartAxis.java
index 12ac3912b1..4c198c0084 100644
--- a/poi-ooxml/src/test/java/org/apache/poi/xssf/usermodel/charts/TestXSSFChartAxis.java
+++ b/poi-ooxml/src/test/java/org/apache/poi/xssf/usermodel/charts/TestXSSFChartAxis.java
@@ -17,11 +17,6 @@
 
 package org.apache.poi.xssf.usermodel.charts;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 import java.io.IOException;
 import java.util.List;
 
@@ -38,6 +33,8 @@ import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.*;
+
 public final class TestXSSFChartAxis {
 
     private static final double EPSILON = 1E-7;
@@ -52,6 +49,8 @@ public final class TestXSSFChartAxis {
         XSSFClientAnchor anchor = drawing.createAnchor(0, 0, 0, 0, 1, 1, 10, 30);
         XSSFChart chart = drawing.createChart(anchor);
         axis = chart.createValueAxis(AxisPosition.BOTTOM);
+        // no format set yet
+        assertNull(axis.getNumberFormat());
     }
 
     @AfterEach