Simplify ReadXml and update test to proof settings are only added to appropriate package

Author: manfred-brands

src/NUnitEngine/nunit.engine.api/TestPackage.cs

@@ -152,9 +152,8 @@ public XmlSchema GetSchema()
         /// <inheritdoc />
         public void ReadXml(XmlReader xmlReader)
         {
-            var currentPackage = this;
-            currentPackage.ID = xmlReader.GetAttribute("id");
-            currentPackage.FullName = xmlReader.GetAttribute("fullname");
+            ID = xmlReader.GetAttribute("id");
+            FullName = xmlReader.GetAttribute("fullname");
             if (!xmlReader.IsEmptyElement)
             {
                 while (xmlReader.Read())
@@ -168,14 +167,14 @@ public void ReadXml(XmlReader xmlReader)
                                     // We don't use AddSettings, which copies settings downward.
                                     // Instead, each package handles it's own settings.
                                     while (xmlReader.MoveToNextAttribute())
-                                        currentPackage.Settings.Add(xmlReader.Name, xmlReader.Value);
+                                        Settings.Add(xmlReader.Name, xmlReader.Value);
                                     xmlReader.MoveToElement();
                                     break;
 
                                 case "TestPackage":
                                     TestPackage subPackage = new TestPackage();
                                     subPackage.ReadXml(xmlReader);
-                                    currentPackage.SubPackages.Add(subPackage);
+                                    SubPackages.Add(subPackage);
                                     break;
                             }
                             break;

src/NUnitEngine/nunit.engine.core.tests/Internal/TestPackageSerializationTests.cs

@@ -17,12 +17,13 @@ public class TestPackageSerializationTests
 
         static TestPackageSerializationTests() 
         {
-            TEST_PACKAGE = new TestPackage(new string[] { "mock-assembly.dll", "notest-assembly.dll" });
+            TEST_PACKAGE = new TestPackage(new string[] { ASSEMBLY_1, ASSEMBLY_2 });
             TEST_PACKAGE.AddSetting("foo", "bar");
+            TEST_PACKAGE.SubPackages[0].AddSetting("cpu", "x86");
 
             TEST_PACKAGE_XML =
                 $"<TestPackage id=\"{TEST_PACKAGE.ID}\"><Settings foo=\"bar\" />" +
-                $"<TestPackage id=\"{TEST_PACKAGE.SubPackages[0].ID}\" fullname=\"{Path.GetFullPath(ASSEMBLY_1)}\"><Settings foo=\"bar\" /></TestPackage>" +
+                $"<TestPackage id=\"{TEST_PACKAGE.SubPackages[0].ID}\" fullname=\"{Path.GetFullPath(ASSEMBLY_1)}\"><Settings foo=\"bar\" cpu=\"x86\" /></TestPackage>" +
                 $"<TestPackage id=\"{TEST_PACKAGE.SubPackages[1].ID}\" fullname=\"{Path.GetFullPath(ASSEMBLY_2)}\"><Settings foo=\"bar\" /></TestPackage>" +
                 "</TestPackage>";