[msbuild] Don't leave changes behind if a test fails. (#7636)

msbuild/tests/Xamarin.iOS.Tasks.Tests/TargetTests/TargetTests.cs

@@ -504,20 +504,24 @@ namespace Xamarin.iOS.Tasks
 			plist.SetMinimumOSVersion ("7.0");
 			plist.Save (path, true);
 
-			var projectInstance = project.CreateProjectInstance ();
-			RunTargetOnInstance (projectInstance, TargetName.CompileImageAssets, 0);
+			ProjectInstance projectInstance = null;
+			try {
+				projectInstance = project.CreateProjectInstance ();
+				RunTargetOnInstance (projectInstance, TargetName.CompileImageAssets, 0);
 
-			var bundleItemsNoAppIcon = projectInstance.GetItems ("_BundleResourceWithLogicalName").ToArray ();
-			Assert.IsFalse (bundleItemsNoAppIcon.Any (i => i.EvaluatedInclude == Path.Combine (actool, "AppIcons60x60@2x.png") && i.GetMetadataValue ("LogicalName") == "AppIcons60x60@2x.png"), "#1");
+				var bundleItemsNoAppIcon = projectInstance.GetItems ("_BundleResourceWithLogicalName").ToArray ();
+				Assert.IsFalse (bundleItemsNoAppIcon.Any (i => i.EvaluatedInclude == Path.Combine (actool, "AppIcons60x60@2x.png") && i.GetMetadataValue ("LogicalName") == "AppIcons60x60@2x.png"), "#1");
 
-			project = SetupProject (Engine, MonoTouchProjectCSProjPath);
-			projectInstance = project.CreateProjectInstance ();
+				project = SetupProject (Engine, MonoTouchProjectCSProjPath);
+				projectInstance = project.CreateProjectInstance ();
 
-			// Put a thread.sleep so that we get noticeable timestamps.
-			EnsureFilestampChange ();
+				// Put a thread.sleep so that we get noticeable timestamps.
+				EnsureFilestampChange ();
 
-			// Re-save the original plist (adding app icon).
-			plistCopy.Save (path, true);
+			} finally {
+				// Re-save the original plist (adding app icon).
+				plistCopy.Save (path, true);
+			}
 
 			// Re-run the task with app icon set this time and no clean.
 			// The task should be aware the app icon is now being used.

msbuild/tests/Xamarin.iOS.Tasks.Tests/TaskTests/GeneratePlistTaskTests/GeneratePlistTaskTests_Core.cs

@@ -55,6 +55,13 @@ namespace Xamarin.iOS.Tasks
 			CompiledPlist = PDictionary.FromFile (Task.CompiledAppManifest.ItemSpec);
 		}
 
+		public override void Teardown ()
+		{
+			base.Teardown ();
+
+			Directory.Delete ("AppBundlePath", true);
+		}
+
 		#region General tests
 		[Test]
 		public void PlistMissing ()