Issue #17106: Fix a segmentation fault in io.TextIOWrapper when an underlying

stream or a decoder produces data of an unexpected type (i.e. when
io.TextIOWrapper initialized with text stream or use bytes-to-bytes codec).

diff --cc Lib/test/test_io.py
Simple merge

diff --cc Misc/NEWS
index 28cc313db12d15276fa63a9f9fc904edcd036f7b,6f8084e0a1cbf039b1311816d77e1603a3289fec..71bd91a5478df14fa5c8d22f2c161a191d8b4eb6
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -235,10 -163,10 +235,14 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #17106: Fix a segmentation fault in io.TextIOWrapper when an underlying
+   stream or a decoder produces data of an unexpected type (i.e. when
+   io.TextIOWrapper initialized with text stream or use bytes-to-bytes codec).
+ 
 +- Issue #17015: When it has a spec, a Mock object now inspects its signature
 +  when matching calls, so that arguments can be matched positionally or
 +  by name.
 +
  - Issue #15633: httplib.HTTPResponse is now mark closed when the server
    sends less than the advertised Content-Length.
  

diff --cc Modules/_io/textio.c
Simple merge