Issue #8203: Fix IDLE Credits dialog: view_file() uses its encoding argument.

Lib/idlelib/textView.py

@@ -62,11 +62,7 @@ def view_text(parent, title, text):
 
 def view_file(parent, title, filename, encoding=None):
     try:
-        if encoding:
-            import codecs
-            textFile = codecs.open(filename, 'r')
-        else:
-            textFile = open(filename, 'r')
+        textFile = open(filename, 'r', encoding=encoding)
     except IOError:
         import tkinter.messagebox as tkMessageBox
         tkMessageBox.showerror(title='File Load Error',

Misc/NEWS

@@ -2047,6 +2047,8 @@ Installation
 Library
 -------
 
+- Issue #8203: Fix IDLE Credits dialog: view_file() uses its encoding argument.
+
 - Issue #5311: bdist_msi can now build packages that do not depend on a
   specific Python version.