Do not uninstall a NuGet package if the project does not reference it.

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

@@ -25,7 +25,9 @@ namespace ICSharpCode.PackageManagement
 			var actions = new List<ProcessPackageAction>();
 			foreach (IPackageManagementSelectedProject selectedProject in selectedProjects) {
 				ProcessPackageAction action = CreatePackageAction(selectedProject);
-				actions.Add(action);
+				if (action != null) {
+					actions.Add(action);
+				}
 			}
 			return actions;
 		}
@@ -35,7 +37,22 @@ namespace ICSharpCode.PackageManagement
 			if (selectedProject.IsSelected) {
 				return base.CreateInstallPackageAction(selectedProject);
 			}
-			return base.CreateUninstallPackageAction(selectedProject);
+			return CreateUninstallPackageActionForSelectedProject(selectedProject);
+		}
+		
+		ProcessPackageAction CreateUninstallPackageActionForSelectedProject(IPackageManagementSelectedProject selectedProject)
+		{
+			ProcessPackageAction action = base.CreateUninstallPackageAction(selectedProject);
+			if (IsPackageInstalled(action.Project)) {
+				return action;
+			}
+			return null;
+		}
+		
+		bool IsPackageInstalled(IPackageManagementProject project)
+		{
+			IPackage package = GetPackage();
+			return project.IsPackageInstalled(package);
 		}
 		
 		protected override bool AnyProjectsSelected(IList<IPackageManagementSelectedProject> projects)

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

@@ -71,6 +71,18 @@ namespace PackageManagement.Tests
 			fakeSolution.AddFakeProjectToReturnFromGetProject(projectName2);
 		}
 		
+		void AddViewModelPackageToTwoSelectedProjectPackages(string projectName1, string projectName2)
+		{
+			FakePackage package = viewModel.FakePackage;
+			fakeSolution.FakeProjectsToReturnFromGetProject[projectName1].FakePackages.Add(package);
+			fakeSolution.FakeProjectsToReturnFromGetProject[projectName2].FakePackages.Add(package);
+		}
+
+		void AddViewModelPackageToFirstSelectedProjectPackages()
+		{
+			FirstSelectedProject.FakeProject.FakePackages.Add(viewModel.FakePackage);
+		}
+		
 		[Test]
 		public void GetProcessPackageActionsForSelectedProjects_OneProjectIsSelected_ReturnsOneAction()
 		{
@@ -112,6 +124,7 @@ namespace PackageManagement.Tests
 			CreateViewModel();
 			CreateOneFakeSelectedProject("Test");
 			FirstSelectedProject.IsSelected = false;
+			AddViewModelPackageToFirstSelectedProjectPackages();
 			GetPackageActionsForSelectedProjects();
 			
 			var action = packageActions[0] as UninstallPackageAction;
@@ -141,6 +154,7 @@ namespace PackageManagement.Tests
 			CreateViewModel();
 			CreateOneFakeSelectedProject("Test");
 			FirstSelectedProject.IsSelected = false;
+			AddViewModelPackageToFirstSelectedProjectPackages();
 			GetPackageActionsForSelectedProjects();
 			
 			var action = packageActions[0] as UninstallPackageAction;
@@ -170,6 +184,7 @@ namespace PackageManagement.Tests
 			CreateViewModel();
 			CreateOneFakeSelectedProject("Test");
 			FirstSelectedProject.IsSelected = false;
+			AddViewModelPackageToFirstSelectedProjectPackages();
 			GetPackageActionsForSelectedProjects();
 			
 			ILogger logger = FirstSelectedProject.Project.Logger;
@@ -178,11 +193,24 @@ namespace PackageManagement.Tests
 			Assert.AreEqual(expectedLogger, logger);
 		}
 		
+		[Test]
+		public void GetProcessPackageActionsForSelectedProjects_OneProjectWithIsSelectedSetToFalseButPackageDoesNotExistInProject_NoActionsReturned()
+		{
+			CreateViewModel();
+			CreateOneFakeSelectedProject("Test");
+			FirstSelectedProject.IsSelected = false;
+			GetPackageActionsForSelectedProjects();
+		
+			Assert.AreEqual(0, packageActions.Count);
+		}
+		
 		[Test]
 		public void ManagePackage_SolutionWithTwoProjectsAndUserUnselectsBothProjects_TwoProjectsAreUninstalled()
 		{
 			CreateViewModelWithTwoProjectsSelected("Project A", "Project B");
 			viewModel.FakePackageManagementEvents.OnSelectProjectsReturnValue = true;
+			AddViewModelPackageToTwoSelectedProjectPackages("Project A", "Project B");
+			viewModel.FakePackageManagementEvents.ProjectsToSelect.Add("UnknownProject");
 			viewModel.ManagePackage();
 			
 			List<ProcessPackageAction> actions = fakeActionRunner.GetActionsRunInOneCallAsList();