Feature: Show confirmation dialog when the undo operation is to delete items. (#11185)

Author: hishitetsu

src/Files.App/Filesystem/StorageHistory/Helpers/StorageHistoryHelpers.cs

@@ -22,13 +22,18 @@ public async Task<ReturnResult> TryUndo()
 				{
 					return ReturnResult.InProgress;
 				}
+				bool keepHistory = false;
 				try
 				{
-					return await operations.Undo(App.HistoryWrapper.GetCurrentHistory());
+					ReturnResult result = await operations.Undo(App.HistoryWrapper.GetCurrentHistory());
+					keepHistory = result is ReturnResult.Cancelled;
+					return result;
 				}
 				finally
 				{
-					App.HistoryWrapper.DecreaseIndex();
+					if (!keepHistory)
+						App.HistoryWrapper.DecreaseIndex();
+
 					semaphore.Release();
 				}
 			}

src/Files.App/Filesystem/StorageHistory/StorageHistoryOperations.cs

@@ -38,13 +38,13 @@ public async Task<ReturnResult> Undo(IStorageHistory history)
 				case FileOperationType.CreateNew: // Opposite: Delete created items
 					if (!IsHistoryNull(history.Source))
 					{
-						return await helpers.DeleteItemsAsync(history.Source, false, true, false);
+						return await helpers.DeleteItemsAsync(history.Source, true, true, false); // Show a dialog to prevent unexpected deletion
 					}
 					break;
 				case FileOperationType.CreateLink: // Opposite: Delete created items
 					if (!IsHistoryNull(history.Destination))
 					{
-						return await helpers.DeleteItemsAsync(history.Destination, false, true, false);
+						return await helpers.DeleteItemsAsync(history.Destination, true, true, false); // Show a dialog to prevent unexpected deletion
 					}
 					break;
 				case FileOperationType.Rename: // Opposite: Restore original item names
@@ -61,7 +61,7 @@ public async Task<ReturnResult> Undo(IStorageHistory history)
 				case FileOperationType.Copy: // Opposite: Delete copied items
 					if (!IsHistoryNull(history.Destination))
 					{
-						return await helpers.DeleteItemsAsync(history.Destination, false, true, false);
+						return await helpers.DeleteItemsAsync(history.Destination, true, true, false); // Show a dialog to prevent unexpected deletion
 					}
 					break;
 				case FileOperationType.Move: // Opposite: Move the items to original directory