#25: return true if file isn't empty, think if bool return value makes sense here

GBase/DataHandling/XmlDataWriter.cs

@@ -31,7 +31,7 @@ namespace GBase.DataHandling
         {
             //if the xml file isn't empty, return
             if (file.Length > 3) //> 3 because of BOM
-                return false;
+                return true; //TODO: Don't return bool?
             
             XDocument xmlDocument = new XDocument();
             xmlDocument.Add(new XElement(rootElementName));
@@ -74,6 +74,7 @@ namespace GBase.DataHandling
             if (typeName == null)
                 throw new ArgumentNullException(nameof(typeName));
             
+            file.Seek(0, SeekOrigin.Begin); //reset stream to it's beginning to be able to save it
             XDocument xmlDocument = await XDocument.LoadAsync(file, LoadOptions.None, cancellationToken);
             file.Seek(0, SeekOrigin.Begin); //reset stream to it's beginning to be able to save it