Fix NullReferenceException in SwitchPackagesToProjectsCommand (#157)

* Check for null reference before accessing Include

* Bump version from 2.1.0 to 2.1.1

Author: cluen

src/Dnt.Commands/Packages/SwitchProjectsToPackagesCommand.cs

@@ -204,7 +204,7 @@ where string.Equals(r.Name, projectName, StringComparison.OrdinalIgnoreCase)
             {
                 var reference = switchedProject.GetSwitchedPackage(packageName);
 
-                if (!string.IsNullOrEmpty(reference.Include))
+                if (reference != null && !string.IsNullOrEmpty(reference.Include))
                 {
                     project.AddItem("Reference", reference.Include, reference.Metadata);
                 }

src/Dnt/Dnt.csproj

@@ -10,7 +10,7 @@
 		<Authors>Rico Suter</Authors>
 		<Company>Rico Suter</Company>
 		<Product>DotNetTools (DNT)</Product>
-		<Version>2.1.0</Version>
+		<Version>2.1.1</Version>
 		<PackageId>DNT</PackageId>
 		<DebugType>embedded</DebugType>
 		<PackAsTool>true</PackAsTool>
@@ -36,4 +36,4 @@
 		<PackageReference Include="Microsoft.Build" Version="17.12.6" ExcludeAssets="runtime" />
 		<PackageReference Include="Microsoft.Build.Utilities.Core" Version="17.12.6" ExcludeAssets="runtime" />
 	</ItemGroup>
-</Project>
+</Project>