Do not show pre-release NuGet packages in Manage Packages dialog.

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

@@ -43,13 +43,9 @@ namespace ICSharpCode.PackageManagement
 		
 		protected override IEnumerable<IPackage> GetFilteredPackagesBeforePagingResults(IQueryable<IPackage> allPackages)
 		{
-			IEnumerable<IPackage> filteredPackages = base.GetFilteredPackagesBeforePagingResults(allPackages);
-			return GetDistinctPackagesById(filteredPackages);
-		}
-		
-		IEnumerable<IPackage> GetDistinctPackagesById(IEnumerable<IPackage> allPackages)
-		{
-			return allPackages.DistinctLast<IPackage>(PackageEqualityComparer.Id);
+			return base.GetFilteredPackagesBeforePagingResults(allPackages)
+				.Where(package => package.IsReleaseVersion())
+				.DistinctLast(PackageEqualityComparer.Id);
 		}
 	}
 }

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

@@ -358,5 +358,29 @@ namespace PackageManagement.Tests
 			ApplicationException ex = Assert.Throws<ApplicationException>(() => CompleteReadPackagesTask());
 			Assert.AreEqual("Test", ex.Message);
 		}
+		
+		[Test]
+		public void ReadPackages_RepositoryHasPrereleaseAndReleasePackage_HasReleasePackageOnly()
+		{
+			CreateViewModel();
+			
+			var releasePackage = new FakePackage("Test", "1.0.0.0");
+			var prereleasePackage = new FakePackage("Test", "1.1.0-alpha");
+			
+			var packages = new FakePackage[] {
+				releasePackage, prereleasePackage
+			};
+			
+			registeredPackageRepositories.FakeActiveRepository.FakePackages.AddRange(packages);
+			
+			viewModel.ReadPackages();
+			CompleteReadPackagesTask();
+			
+			var expectedPackages = new FakePackage[] {
+				releasePackage
+			};
+			
+			PackageCollectionAssert.AreEqual(expectedPackages, viewModel.PackageViewModels);
+		}
 	}
 }