bpo-30681: Support invalid date format or value in email Date header (GH-22090)
I am re-submitting an older PR which was abandoned but is still relevant, #10783 by @timb07.
The issue being solved () is still relevant. The original PR #10783 was closed as
the final request changes were not applied and since abandoned.
In this new PR I have re-used the original patch plus applied both comments from the review, by @maxking and @pganssle.
For reference, here is the original PR description:
In email.utils.parsedate_to_datetime(), a failure to parse the date, or invalid date components (such as hour outside 0..23) raises an exception. Document this behaviour, and add tests to test_email/test_utils.py to confirm this behaviour.
In email.headerregistry.DateHeader.parse(), check when parsedate_to_datetime() raises an exception and add a new defect InvalidDateDefect; preserve the invalid value as the string value of the header, but set the datetime attribute to None.
Add tests to test_email/test_headerregistry.py to confirm this behaviour; also added test to test_email/test_inversion.py to confirm emails with such defective date headers round trip successfully.
This pull request incorporates feedback gratefully received from @bitdancer, @brettcannon, @Mariatta and @warsaw, and replaces the earlier PR #2254.
Automerge-Triggered-By: GH:warsaw
diff --git a/Lib/email/_parseaddr.py b/Lib/email/_parseaddr.py
index 41ff6f8..4d27f87 100644
--- a/Lib/email/_parseaddr.py
+++ b/Lib/email/_parseaddr.py
@@ -65,7 +65,7 @@ def _parsedate_tz(data):
"""
if not data:
- return
+ return None
data = data.split()
# The FWS after the comma after the day-of-week is optional, so search and
# adjust for this.
diff --git a/Lib/email/errors.py b/Lib/email/errors.py
index d28a680..1d258c3 100644
--- a/Lib/email/errors.py
+++ b/Lib/email/errors.py
@@ -108,3 +108,6 @@ class NonASCIILocalPartDefect(HeaderDefect):
"""local_part contains non-ASCII characters"""
# This defect only occurs during unicode parsing, not when
# parsing messages decoded from binary.
+
+class InvalidDateDefect(HeaderDefect):
+ """Header has unparseable or invalid date"""
diff --git a/Lib/email/headerregistry.py b/Lib/email/headerregistry.py
index 5d84fc0..d8613eb 100644
--- a/Lib/email/headerregistry.py
+++ b/Lib/email/headerregistry.py
@@ -302,7 +302,14 @@ def parse(cls, value, kwds):
kwds['parse_tree'] = parser.TokenList()
return
if isinstance(value, str):
- value = utils.parsedate_to_datetime(value)
+ kwds['decoded'] = value
+ try:
+ value = utils.parsedate_to_datetime(value)
+ except ValueError:
+ kwds['defects'].append(errors.InvalidDateDefect('Invalid date value or format'))
+ kwds['datetime'] = None
+ kwds['parse_tree'] = parser.TokenList()
+ return
kwds['datetime'] = value
kwds['decoded'] = utils.format_datetime(kwds['datetime'])
kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
diff --git a/Lib/email/utils.py b/Lib/email/utils.py
index 1a7719d..a8e46a7 100644
--- a/Lib/email/utils.py
+++ b/Lib/email/utils.py
@@ -195,7 +195,10 @@ def make_msgid(idstring=None, domain=None):
def parsedate_to_datetime(data):
- *dtuple, tz = _parsedate_tz(data)
+ parsed_date_tz = _parsedate_tz(data)
+ if parsed_date_tz is None:
+ raise ValueError('Invalid date value or format "%s"' % str(data))
+ *dtuple, tz = parsed_date_tz
if tz is None:
return datetime.datetime(*dtuple[:6])
return datetime.datetime(*dtuple[:6],