There was an error in the Tk error dialog fix at Rev 1.84 which caused starting w/o the subprocess to fail.  Check in a fix to IDLE and IDLEfork.
There was an error in the Tk error dialog fix at Rev 1.84 which caused starting
w/o the subprocess to fail.  Check in a fix to IDLE and IDLEfork.

M PyShell.py

Backport candidate, combine with previous.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator