(merge 3.2) Issue #12467: warnings: fix a race condition if a warning is

emitted at shutdown, if globals()['__file__'] is None.

diff --cc Misc/NEWS
index 9aba95e98f2aa21479ec1a04874c86eca1711587,401a8eaf7f29ac249f0af1256e0c19c464d7eea4..7fb3c929b8f608ef35e2e3e022c25cdec9017c6f
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -209,16 -61,6 +209,19 @@@ Core and Builtin
  Library
  -------
  
++- Issue #12467: warnings: fix a race condition if a warning is emitted at
++  shutdown, if globals()['__file__'] is None.
++
 +- Issue #12451: pydoc: importfile() now opens the Python script in binary mode,
 +  instead of text mode using the locale encoding, to avoid encoding issues.
 +
 +- Issue #12451: runpy: run_path() now opens the Python script in binary mode,
 +  instead of text mode using the locale encoding, to support other encodings
 +  than UTF-8 (scripts using the coding cookie).
 +
 +- Issue #12451: xml.dom.pulldom: parse() now opens files in binary mode instead
 +  of the text mode (using the locale encoding) to avoid encoding issues.
 +
  - Issue #12147: Adjust the new-in-3.2 smtplib.send_message method for better
    conformance to the RFCs:  correctly handle Sender and Resent- headers.