Diff doesn't detect UTF-8 without BOM

The diff section of the application will show all text as ASCII when a file is encoded in UTF-8 without BOM. The way I confirmed that it was ASCII was by switching to ASCII mode inside Notepad++ and I got an identical set of garbled text. I attached images of one instance of this in the diff view, and in Notepad++. Furthermore, UTF-8 without BOM shows a miscellaneous character as the first character of the document. Adding a BOM caused the application to detect the file correctly, however using BOM with UTF-8 is not recommended by the Unicode standard (section 2.6).