Fix pre-release NuGet packages always being installed.

Pre-release NuGet packages can now only be installed with the Package Management
console when the -IncludePrerelease argument is specified.

src/AddIns/Misc/PackageManagement/Project/Src/InstallPackageAction.cs

@@ -19,7 +19,6 @@ namespace ICSharpCode.PackageManagement
 		}
 		
 		public bool IgnoreDependencies { get; set; }
-		public bool AllowPrereleaseVersions { get; set; }
 		
 		protected override IEnumerable<PackageOperation> GetPackageOperations()
 		{

src/AddIns/Misc/PackageManagement/Project/Src/ProcessPackageAction.cs

@@ -26,6 +26,7 @@ namespace ICSharpCode.PackageManagement
 		public SemanticVersion PackageVersion { get; set; }
 		public string PackageId { get; set; }
 		public IPackageScriptRunner PackageScriptRunner { get; set; }
+		public bool AllowPrereleaseVersions { get; set; }
 		
 		public virtual bool HasPackageScriptsToRun()
 		{
@@ -97,13 +98,20 @@ namespace ICSharpCode.PackageManagement
 		void GetPackageIfMissing()
 		{
 			if (Package == null) {
-				Package = Project.SourceRepository.FindPackage(PackageId, PackageVersion);
+				FindPackage();
 			}
 			if (Package == null) {
 				ThrowPackageNotFoundError(PackageId);
 			}
 		}
 		
+		void FindPackage()
+		{
+			Package =Project
+				.SourceRepository
+				.FindPackage(PackageId, PackageVersion, AllowPrereleaseVersions, allowUnlisted: true);
+		}
+		
 		void ThrowPackageNotFoundError(string packageId)
 		{
 			string message = String.Format("Unable to find package '{0}'.", packageId);

src/AddIns/Misc/PackageManagement/Project/Src/UninstallPackageAction.cs

@@ -15,6 +15,7 @@ namespace ICSharpCode.PackageManagement
 			IPackageManagementEvents packageManagementEvents)
 			: base(project, packageManagementEvents)
 		{
+			this.AllowPrereleaseVersions = true;
 		}
 		
 		public bool ForceRemove { get; set; }

src/AddIns/Misc/PackageManagement/Project/Src/UpdatePackageAction.cs

@@ -20,7 +20,6 @@ namespace ICSharpCode.PackageManagement
 		
 		public bool UpdateDependencies { get; set; }
 		public bool UpdateIfPackageDoesNotExistInProject { get; set; }
-		public bool AllowPrereleaseVersions { get; set; }
 		
 		protected override IEnumerable<PackageOperation> GetPackageOperations()
 		{

src/AddIns/Misc/PackageManagement/Test/Src/InstallPackageActionTests.cs

@@ -342,6 +342,47 @@ namespace PackageManagement.Tests
 			Assert.AreEqual(expectedPackage, actualPackage);
 		}
 		
+		[Test]
+		public void Execute_InstallPrereleasePackageAndAllowPreleasePackagesIsFalse_DoesNotFindPreleasePackage()
+		{
+			CreateAction();
+			FakePackage package = fakeProject.FakeSourceRepository.AddFakePackageWithVersion("Prerelease", "1.0-beta");
+			action.PackageId = "Prerelease";
+			action.AllowPrereleaseVersions = false;
+			
+			Exception ex = Assert.Throws(typeof(ApplicationException), () => action.Execute());
+			
+			Assert.AreEqual("Unable to find package 'Prerelease'.", ex.Message);
+		}
+		
+		[Test]
+		public void Execute_InstallPrereleasePackageAndAllowPreleasePackagesIsTrue_InstallsPackageIntoProject()
+		{
+			CreateAction();
+			FakePackage expectedPackage = fakeProject.FakeSourceRepository.AddFakePackageWithVersion("Prerelease", "1.0-beta");
+			action.PackageId = "Prerelease";
+			action.AllowPrereleaseVersions = true;
+			
+			action.Execute();
+			
+			IPackage actualPackage = fakeProject.PackagePassedToInstallPackage;
+			Assert.AreEqual(expectedPackage, actualPackage);
+		}
+		
+		[Test]
+		public void Execute_InstallUnlistedPackage_InstallsPackageIntoProject()
+		{
+			CreateAction();
+			FakePackage expectedPackage = fakeProject.FakeSourceRepository.AddFakePackageWithVersion("test", "1.0");
+			expectedPackage.Listed = false;
+			action.PackageId = "test";
+			
+			action.Execute();
+			
+			IPackage actualPackage = fakeProject.PackagePassedToInstallPackage;
+			Assert.AreEqual(expectedPackage, actualPackage);
+		}
+		
 		[Test]
 		public void Execute_PackageIdSpecifiedButDoesNotExistInRepository_ExceptionThrown()
 		{

src/AddIns/Misc/PackageManagement/Test/Src/UninstallPackageActionTests.cs

@@ -212,5 +212,14 @@ namespace PackageManagement.Tests
 			
 			Assert.IsTrue(hasPackageScripts);
 		}
+		
+		[Test]
+		public void AllowPreleasePackages_DefaultValue_IsTrue()
+		{
+			CreateAction();
+			
+			Assert.IsTrue(action.AllowPrereleaseVersions);
+		}
+		
 	}
 }