…ed-string (pythonGH-122753) (pythonGH-129111)
Email generators using email.policy.default could incorrectly omit the
quote ('"') characters from a quoted-string during header refolding,
leading to invalid address headers and enabling header spoofing. This
change restores the quote characters on a bare-quoted-string as the
header is refolded, and escapes backslash and quote chars in the string.
(cherry picked from commit 5aaf416)
(cherry picked from commit a4ef689)
Co-authored-by: R. David Murray <rdmurray@bitdance.com>
Co-authored-by: Mike Edmunds <medmunds@gmail.com>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>