Fix race condition when searching for NuGet packages.

src/AddIns/Misc/PackageManagement/Project/PackageManagement.csproj

@@ -232,6 +232,7 @@
     <Compile Include="Src\PackageManagementServiceProvider.cs" />
     <Compile Include="Src\IPackageRepositoryExtensions.cs" />
     <Compile Include="Src\PackageRepositoryFactoryEventArgs.cs" />
+    <Compile Include="Src\PackagesForSelectedPageQuery.cs" />
     <Compile Include="Src\ParentPackagesOperationEventArgs.cs" />
     <Compile Include="Src\ProjectBuilder.cs" />
     <Compile Include="Src\ProjectRootElementExtensions.cs" />

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

@@ -84,7 +84,7 @@ namespace ICSharpCode.PackageManagement
 					.Where(package => package.IsAbsoluteLatestVersion);
 			}
 			return repository
-				.Search(SearchTerms, IncludePrerelease)
+				.Search(searchCriteria, IncludePrerelease)
 				.Where(package => package.IsLatestVersion);
 		}
 		

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

@@ -0,0 +1,32 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using System.Collections.Generic;
+
+using NuGet;
+
+namespace ICSharpCode.PackageManagement
+{
+	public class PackagesForSelectedPageQuery
+	{
+		public PackagesForSelectedPageQuery (
+			PackagesViewModel viewModel,
+			IEnumerable<IPackage> allPackages,
+			string searchCriteria)
+		{
+			Skip = viewModel.ItemsBeforeFirstPage;
+			Take = viewModel.PageSize;
+			AllPackages = allPackages;
+			SearchCriteria = searchCriteria;
+			TotalPackages = viewModel.TotalItems;
+		}
+
+		public int Skip { get; private set; }
+		public int Take { get; private set; }
+		public string SearchCriteria { get; private set; }
+
+		public int TotalPackages { get; set; }
+		public IEnumerable<IPackage> AllPackages { get; set; }
+	}
+}

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

@@ -26,15 +26,19 @@ namespace ICSharpCode.PackageManagement
 {
 	public class PackagesForSelectedPageResult
 	{
-		public PackagesForSelectedPageResult(IEnumerable<IPackage> packages, int totalPackages)
+		public PackagesForSelectedPageResult(IEnumerable<IPackage> packages, PackagesForSelectedPageQuery query)
 		{
 			this.Packages = packages;
 			this.TotalPackagesOnPage = packages.Count();
-			this.TotalPackages = totalPackages;
+			this.TotalPackages = query.TotalPackages;
+			this.AllPackages = query.AllPackages;
+			this.Query = query;
 		}
 		
+		public PackagesForSelectedPageQuery Query { get; set; }
 		public IEnumerable<IPackage> Packages { get; set; }
 		public int TotalPackagesOnPage { get; set; }
 		public int TotalPackages { get; set; }
+		public IEnumerable<IPackage> AllPackages { get; set; }
 	}
 }

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

@@ -41,6 +41,7 @@ namespace ICSharpCode.PackageManagement
 		IEnumerable<IPackage> allPackages;
 		ITask<PackagesForSelectedPageResult> task;
 		bool includePrerelease;
+		PackagesForSelectedPageQuery packagesForSelectedPageQuery;
 		
 		public PackagesViewModel(
 			IPackageManagementSolution solution,
@@ -153,15 +154,18 @@ namespace ICSharpCode.PackageManagement
 		
 		void CreateReadPackagesTask()
 		{
+			var query = new PackagesForSelectedPageQuery(this, allPackages, GetSearchCriteria());
+			packagesForSelectedPageQuery = query;
+			
 			task = taskFactory.CreateTask(
-				() => GetPackagesForSelectedPageResult(),
+				() => GetPackagesForSelectedPageResult(query),
 				OnPackagesReadForSelectedPage);
 		}
 
-		PackagesForSelectedPageResult GetPackagesForSelectedPageResult()
+		PackagesForSelectedPageResult GetPackagesForSelectedPageResult(PackagesForSelectedPageQuery query)
 		{
-			IEnumerable<IPackage> packages = GetPackagesForSelectedPage();
-			return new PackagesForSelectedPageResult(packages, TotalItems);
+			IEnumerable<IPackage> packages = GetPackagesForSelectedPage(query);
+			return new PackagesForSelectedPageResult(packages, query);
 		}
 		
 		void OnPackagesReadForSelectedPage(ITask<PackagesForSelectedPageResult> task)
@@ -171,12 +175,19 @@ namespace ICSharpCode.PackageManagement
 				SaveError(task.Exception);
 			} else if (task.IsCancelled) {
 				// Ignore
+			} else if (!IsCurrentQuery(task.Result)) {
+				// Ignore.
 			} else {
 				UpdatePackagesForSelectedPage(task.Result);
 			}
 			base.OnPropertyChanged(null);
 		}
 		
+		bool IsCurrentQuery(PackagesForSelectedPageResult result)
+		{
+			return packagesForSelectedPageQuery == result.Query;
+		}
+		
 		void SaveError(AggregateException ex)
 		{
 			HasError = true;
@@ -194,6 +205,8 @@ namespace ICSharpCode.PackageManagement
 		{
 			pages.TotalItems = result.TotalPackages;
 			pages.TotalItemsOnSelectedPage = result.TotalPackagesOnPage;
+			TotalItems = result.TotalPackages;
+			allPackages = result.AllPackages;
 			UpdatePackageViewModels(result.Packages);
 		}
 		
@@ -203,20 +216,20 @@ namespace ICSharpCode.PackageManagement
 			base.OnPropertyChanged(null);
 		}
 		
-		IEnumerable<IPackage> GetPackagesForSelectedPage()
+		IEnumerable<IPackage> GetPackagesForSelectedPage(PackagesForSelectedPageQuery query)
 		{
-			IEnumerable<IPackage> filteredPackages = GetFilteredPackagesBeforePagingResults();
-			return GetPackagesForSelectedPage(filteredPackages);
+			IEnumerable<IPackage> filteredPackages = GetFilteredPackagesBeforePagingResults(query);
+			return GetPackagesForSelectedPage(filteredPackages, query);
 		}
 		
-		IEnumerable<IPackage> GetFilteredPackagesBeforePagingResults()
+		IEnumerable<IPackage> GetFilteredPackagesBeforePagingResults(PackagesForSelectedPageQuery query)
 		{
-			if (allPackages == null) {
-				IQueryable<IPackage> packages = GetPackagesFromPackageSource();
-				TotalItems = packages.Count();
-				allPackages = GetFilteredPackagesBeforePagingResults(packages);
+			if (query.AllPackages == null) {
+				IQueryable<IPackage> packages = GetPackagesFromPackageSource(query.SearchCriteria);
+				query.TotalPackages = packages.Count();
+				query.AllPackages = GetFilteredPackagesBeforePagingResults(packages);
 			}
-			return allPackages;
+			return query.AllPackages;
 		}
 		
 		/// <summary>
@@ -224,7 +237,12 @@ namespace ICSharpCode.PackageManagement
 		/// </summary>
 		public IQueryable<IPackage> GetPackagesFromPackageSource()
 		{
-			IQueryable<IPackage> packages = GetAllPackages(GetSearchCriteria());
+			return GetPackagesFromPackageSource(GetSearchCriteria());
+		}
+		
+		IQueryable<IPackage> GetPackagesFromPackageSource(string searchCriteria)
+		{
+			IQueryable<IPackage> packages = GetAllPackages(searchCriteria);
 			return OrderPackages(packages);
 		}
 		
@@ -242,12 +260,11 @@ namespace ICSharpCode.PackageManagement
 			return SearchTerms;
 		}
 		
-		IEnumerable<IPackage> GetPackagesForSelectedPage(IEnumerable<IPackage> allPackages)
+		IEnumerable<IPackage> GetPackagesForSelectedPage(IEnumerable<IPackage> allPackages, PackagesForSelectedPageQuery query)
 		{
-			int packagesToSkip = pages.ItemsBeforeFirstPage;
 			return allPackages
-				.Skip(packagesToSkip)
-				.Take(pages.PageSize);
+				.Skip(query.Skip)
+				.Take(query.Take);
 		}
 		
 		/// <summary>
@@ -325,6 +342,10 @@ namespace ICSharpCode.PackageManagement
 			set { pages.PageSize = value; }
 		}
 		
+		public int ItemsBeforeFirstPage {
+			get { return pages.ItemsBeforeFirstPage; }
+		}
+		
 		public bool IsPaged {
 			get { return pages.IsPaged; }
 		}

src/AddIns/Misc/PackageManagement/Test/Src/Helpers/FakeTaskFactory.cs

@@ -51,6 +51,12 @@ namespace PackageManagement.Tests.Helpers
 			}
 		}
 		
+		public void ExecuteTask(int index)
+		{
+			var task = FakeTasksCreated[index] as FakeTask<PackagesForSelectedPageResult>;
+			task.ExecuteTaskCompletely();
+		}
+		
 		public void ClearAllFakeTasks()
 		{
 			FakeTasksCreated.Clear();

src/AddIns/Misc/PackageManagement/Test/Src/Helpers/TestablePackagesViewModel.cs

@@ -64,10 +64,11 @@ namespace PackageManagement.Tests.Helpers
 			AddFakePackage("Test");
 		}
 		
-		public void AddFakePackage(string packageId)
+		public FakePackage AddFakePackage(string packageId)
 		{
 			FakePackage package = CreateFakePackage(packageId);
 			FakePackages.Add(package);
+			return package;
 		}
 		
 		FakePackage CreateFakePackage(string packageId)

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

@@ -333,22 +333,20 @@ namespace PackageManagement.Tests
 		}
 		
 		[Test]
-		public void ReadPackages_RepositoryHasThreePackagesWhenSelectedPageIsOneAndPageSizeIsTwo_TwoPackageViewModelsCreatedForFirstTwoPackages()
+		public void ReadPackages_SecondQueryFinishesBeforeFirst_PackagesInViewModelAreForSecondQuery()
 		{
 			CreateViewModel();
-			viewModel.PageSize = 2;
-			viewModel.SelectedPageNumber = 1;
 			viewModel.AddThreeFakePackages();
+			FakePackage package = viewModel.AddFakePackage("MyTest");
 			viewModel.ReadPackages();
-			CompleteReadPackagesTask();
+			viewModel.SearchTerms = "MyTest";
 			
-			var expectedPackages = new List<FakePackage>();
-			expectedPackages.Add(viewModel.FakePackages[0]);
-			expectedPackages.Add(viewModel.FakePackages[1]);
+			var expectedPackages = new FakePackage [] { package };
 			
-			ClearReadPackagesTasks();
 			viewModel.ReadPackages();
-			CompleteReadPackagesTask();
+			taskFactory.ExecuteTask(1);
+			taskFactory.ExecuteTask(0);
+			ClearReadPackagesTasks();
 			
 			PackageCollectionAssert.AreEqual(expectedPackages, viewModel.PackageViewModels);
 		}
@@ -1072,7 +1070,8 @@ namespace PackageManagement.Tests
 			CreateViewModel();
 			viewModel.AddSixFakePackages();
 			viewModel.ReadPackages();
-			taskFactory.FirstFakeTaskCreated.Result = new PackagesForSelectedPageResult(viewModel.FakePackages, 6);
+			var query = new PackagesForSelectedPageQuery(viewModel, null, null);
+			taskFactory.FirstFakeTaskCreated.Result = new PackagesForSelectedPageResult(viewModel.FakePackages, query);
 			taskFactory.FirstFakeTaskCreated.IsFaulted = true;
 			CompleteReadPackagesTask();