accept None as the same as having passed no argument in file types #7349
This is for consistency with imitation file objects like StringIO and BytesIO.
This commit also adds a few tests, where they were lacking for concerned
methods.
diff --git a/Misc/NEWS b/Misc/NEWS
index 9c08b43..cfdf975 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -20,6 +20,10 @@
Library
-------
+- Issue #7349: Make methods of file objects in the io module accept None as an
+ argument where file-like objects (ie StringIO and BytesIO) accept them to mean
+ the same as passing no argument.
+
- Issue #7348: StringIO.StringIO.readline(-1) now acts as if it got no argument
like other file objects.