fix loading from new file

Author: uazo

SuperPatch.Core/FileContentBuilder.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using DiffPatch.Data;
 
@@ -24,21 +25,36 @@ public class FileContentBuilder
     internal static async Task<FileContents> LoadAsync(Workspace wrk, FileDiff file, Status.StatusDelegate status)
     {
       status?.InvokeAsync($"Loading {file.From}");
-      byte[] fileContent = null;
-      try
-      {
-        fileContent = await wrk.Storage.GetFileAsync(file);
-      }
-      catch(System.Exception ex)
-      {
-        status?.InvokeAsync($"Error {ex.Message}");
-      }
+			string fileContent = null;
+
+			var diffAdd = wrk.PatchsSet
+											.SelectMany(x => x.Diff)
+											.FirstOrDefault(x => x.Type == FileChangeType.Add &&
+																						x.To == file.From);
+			if (diffAdd != null)
+			{
+				fileContent =
+					DiffPatch.PatchHelper.Patch(string.Empty, diffAdd.Chunks, "\n");
+			}
+
+			if (fileContent == null)
+			{
+				try
+				{
+					fileContent = System.Text.Encoding.UTF8.GetString(
+						await wrk.Storage.GetFileAsync(file));
+				}
+				catch (System.Exception ex)
+				{
+					status?.InvokeAsync($"Error {ex.Message}");
+				}
+			}
       status?.InvokeAsync($"Loaded {file.From}");
 
       var contents = new FileContents()
       {
         FileName = file.From,
-        Contents = fileContent == null ? String.Empty : System.Text.Encoding.UTF8.GetString(fileContent),
+        Contents = fileContent ?? string.Empty,
         Status = FileContentsStatus.Loaded
       };
       return contents;