Fix index out of range exception in Package Sources option panel.

Disable move buttons if no package source selected.

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

@@ -170,7 +170,7 @@ namespace ICSharpCode.PackageManagement
 		}
 		
 		public bool CanRemovePackageSource {
-			get { return selectedPackageSourceViewModel != null; }
+			get { return IsPackageSourceSelected(); }
 		}
 		
 		void RemoveSelectedPackageSourceViewModel()
@@ -192,10 +192,17 @@ namespace ICSharpCode.PackageManagement
 		
 		public bool CanMovePackageSourceUp {
 			get {
-				return HasAtLeastTwoPackageSources() && !IsFirstPackageSourceSelected();
+				return HasAtLeastTwoPackageSources() &&
+					IsPackageSourceSelected() &&
+					!IsFirstPackageSourceSelected();
 			}
 		}
 		
+		bool IsPackageSourceSelected()
+		{
+			return selectedPackageSourceViewModel != null;
+		}
+		
 		bool IsFirstPackageSourceSelected()
 		{
 			return selectedPackageSourceViewModel == packageSourceViewModels[0];
@@ -210,7 +217,9 @@ namespace ICSharpCode.PackageManagement
 		
 		public bool CanMovePackageSourceDown {
 			get {
-				return HasAtLeastTwoPackageSources() && !IsLastPackageSourceSelected();
+				return HasAtLeastTwoPackageSources() &&
+					IsPackageSourceSelected() &&
+					!IsLastPackageSourceSelected();
 			}
 		}
 		

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

@@ -445,6 +445,30 @@ namespace PackageManagement.Tests
 			Assert.IsFalse(result);
 		}
 		
+		[Test]
+		public void CanMovePackageSourceUp_TwoPackageSourcesAndNothingIsSelected_ReturnsFalse()
+		{
+			CreateViewModelWithTwoPackageSources();
+			viewModel.Load();
+			viewModel.SelectedPackageSourceViewModel = null;
+			
+			bool result = viewModel.CanMovePackageSourceUp;
+			
+			Assert.IsFalse(result);
+		}
+		
+		[Test]
+		public void CanMovePackageSourceDown_TwoPackageSourcesAndNothingIsSelected_ReturnsFalse()
+		{
+			CreateViewModelWithTwoPackageSources();
+			viewModel.Load();
+			viewModel.SelectedPackageSourceViewModel = null;
+			
+			bool result = viewModel.CanMovePackageSourceDown;
+			
+			Assert.IsFalse(result);
+		}
+		
 		[Test]
 		public void SelectedPackageSourceViewModel_PropertyChanged_FiresPropertyChangedEvent()
 		{