Added more checks on the ExcelCustomXml.Save method - #2254 (#2264)

Author: JanKallman

src/EPPlus/Data/CustomXml/ExcelCustomXml.cs

@@ -44,6 +44,8 @@ internal XmlDocument PropertiesXml
         }
         internal ExcelCustomXml()
         {
+            SchemasReferences = [Schemas.schemaDataMashup];
+            CustomXml = new XmlDocument();
         }
         internal ExcelCustomXml(ZipPackagePart part)
         {
@@ -107,6 +109,7 @@ internal void Save(ExcelPackage pck)
                 var nsm = CreateNsm();
                 _xmlHelper = XmlHelperFactory.Create(nsm, PropertiesXml.DocumentElement.SelectSingleNode("ds:schemaRefs", nsm));
             }
+
             if (_xmlHelper != null)
             {
                 _xmlHelper.TopNode.InnerXml = "";
@@ -117,15 +120,21 @@ internal void Save(ExcelPackage pck)
                     _xmlHelper.TopNode.AppendChild(schemaRefNode);
                 }
             }
-            var xmlSettings = new XmlWriterSettings();
 
-            var stream = Part.GetStream(FileMode.Create, FileAccess.Write);
-            var xmlWriter = XmlWriter.Create(stream, xmlSettings);
-            CustomXml.Save(xmlWriter);
+            var xmlSettings = new XmlWriterSettings();
 
-            stream = PropertiesPart.GetStream(FileMode.Create, FileAccess.Write);
-            xmlWriter = XmlWriter.Create(stream, xmlSettings);
-            PropertiesXml.Save(xmlWriter);
+            if (Part != null)
+            {
+                var stream = Part.GetStream(FileMode.Create, FileAccess.Write);
+                var xmlWriter = XmlWriter.Create(stream, xmlSettings);
+                CustomXml.Save(xmlWriter);
+            }
+            if (PropertiesPart != null)
+            {
+                var stream = PropertiesPart.GetStream(FileMode.Create, FileAccess.Write);
+                var xmlWriter = XmlWriter.Create(stream, xmlSettings);
+                PropertiesXml.Save(xmlWriter);
+            }
         }
     }
 }

src/EPPlus/Data/PowerQuery/ExcelPowerQuerySettings.cs

@@ -266,7 +266,7 @@ internal void Save(ExcelCustomXmlCollection customXml)
 
             if (cx == null)
             {
-                cx = new ExcelCustomXml() { SchemasReferences = { Schemas.schemaDataMashup}, CustomXml = new XmlDocument()  };
+                cx = new ExcelCustomXml();
             }
 
             cx.CustomXml.LoadXml($"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?><DataMashup xmlns=\"{Schemas.schemaDataMashup}\">{Convert.ToBase64String(retMs.ToArray())}</DataMashup>");

src/EPPlusTest/Issues/PackageIssues.cs

@@ -153,5 +153,13 @@ public void i2235()
             sheet.Calculate(o => o.EnableUnicodeAwareStringOperations = true);
             SaveAndCleanup(package);
         }
+        [TestMethod]
+        public void XmlIssue()
+        {
+            using var package = OpenTemplatePackage("test external connection.xlsx");
+            package.Workbook.CalculateAllPivotTables();
+
+            SaveAndCleanup(package);
+        }
     }
 }