[Core] Add unit tests for MSBuildProject.SetMonoDevelopProjectExtension

The xmlns attribute was not being removed for a Sdk style project
when setting a MonoDevelop project extension. However this did not
affect the file being saved. To make things consistent the xmlns
attribute is now removed if it is an empty string and the project is
an Sdk style project.

2 files changed, 46 insertions, 1 deletions

diff --git a/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/MSBuildProject.cs b/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/MSBuildProject.cs
index de52502587..3db8b8c64a 100644
--- a/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/MSBuildProject.cs
+++ b/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/MSBuildProject.cs
@@ -929,7 +929,7 @@ namespace MonoDevelop.Projects.MSBuild
 			}
 			XmlUtil.Indent (format, value, false);
 			var xmlns = value.GetAttribute ("xmlns");
-			if (xmlns == Namespace)
+			if (xmlns == (Namespace ?? string.Empty))
 				value.RemoveAttribute ("xmlns");
 			SetProjectExtension (parent);
 			NotifyChanged ();
diff --git a/main/tests/UnitTests/MonoDevelop.Projects/MSBuildProjectTests.cs b/main/tests/UnitTests/MonoDevelop.Projects/MSBuildProjectTests.cs
index ce15b478b6..2e87dee4e9 100644
--- a/main/tests/UnitTests/MonoDevelop.Projects/MSBuildProjectTests.cs
+++ b/main/tests/UnitTests/MonoDevelop.Projects/MSBuildProjectTests.cs
@@ -793,6 +793,51 @@ namespace MonoDevelop.Projects
 			Assert.AreEqual (1, monoDevelopElement.ChildNodes.Count);
 		}
 
+		[TestCase ("Sdk=\"Microsoft.NET.Sdk\" ToolsVersion=\"15.0\"",
+			"<ExtensionData>Value</ExtensionData>",
+			false)]
+		[TestCase ("Sdk=\"Microsoft.NET.Sdk\" ToolsVersion=\"15.0\"",
+			"<ExtensionData xmlns=\"\">Value</ExtensionData>",
+			false)]
+		[TestCase ("ToolsVersion=\"15.0\" xmlns=\"http://schemas.microsoft.com/developer/msbuild/2003\"",
+			"<ExtensionData>Value</ExtensionData>",
+			true)] // xmlns=''
+		[TestCase ("ToolsVersion=\"15.0\" xmlns=\"http://schemas.microsoft.com/developer/msbuild/2003\"",
+			"<ExtensionData xmlns=\"http://schemas.microsoft.com/developer/msbuild/2003\">Value</ExtensionData>",
+			false)]
+		public void SetMonoDevelopProjectExtension (
+			string projectElementAttributes,
+			string extensionXml,
+			bool expectedHasXmlAttribute)
+		{
+			string projectXml =
+				"<Project " + projectElementAttributes + ">\r\n" +
+				"  <PropertyGroup>\r\n" +
+				"    <TargetFramework>netcoreapp1.0</TargetFramework>\r\n" +
+				"  </PropertyGroup>\r\n" +
+				"</Project>";
+
+			var p = new MSBuildProject ();
+			p.LoadXml (projectXml);
+
+			var doc = new XmlDocument ();
+			doc.LoadXml (extensionXml);
+			var element = doc.DocumentElement;
+			p.SetMonoDevelopProjectExtension ("Test", element);
+
+			string xml = p.SaveToString ();
+			doc = new XmlDocument ();
+			doc.LoadXml (xml);
+
+			var projectExtensions = (XmlElement)doc.DocumentElement.ChildNodes[1];
+			var monoDevelopElement = (XmlElement)projectExtensions.ChildNodes[0];
+			var propertiesElement = (XmlElement)monoDevelopElement.ChildNodes[0];
+			var extensionDataElement = (XmlElement)propertiesElement.ChildNodes[0];
+
+			Assert.AreEqual (expectedHasXmlAttribute, extensionDataElement.HasAttribute ("xmlns"));
+			Assert.AreEqual ("ExtensionData", extensionDataElement.Name);
+		}
+
 		/// <summary>
 		/// This works without any changes to MSBuildProperty using the full
 		/// MSBuild xmlns value.