[3.13] gh-134152: Fix UnboundLocalError in email._header_value_parser _get_ptext_to_e...

Co-authored-by: R. David Murray <rdmurray@bitdance.com>

diff --git a/Lib/email/_header_value_parser.py b/Lib/email/_header_value_parser.py
index 9a51b9437333db8addbe03195afcb86d18068d80..f11fa83d45ed2d39d6631380879ff0664c5b7037 100644 (file)
--- a/Lib/email/_header_value_parser.py
+++ b/Lib/email/_header_value_parser.py
@@ -1020,6 +1020,8 @@ def _get_ptext_to_endchars(value, endchars):
     a flag that is True iff there were any quoted printables decoded.
 
     """
+    if not value:
+        return '', '', False
     fragment, *remainder = _wsp_splitter(value, 1)
     vchars = []
     escape = False

diff --git a/Lib/test/test_email/test__header_value_parser.py b/Lib/test/test_email/test__header_value_parser.py
index 69d4e9ab126d6dbafca02efe6fec818eac80ed3c..60d4dfccba6f925030214322c1faf910a4f3dc38 100644 (file)
--- a/Lib/test/test_email/test__header_value_parser.py
+++ b/Lib/test/test_email/test__header_value_parser.py
@@ -463,6 +463,19 @@ class TestParser(TestParserMixin, TestEmailBase):
                                 [errors.NonPrintableDefect], ')')
         self.assertEqual(ptext.defects[0].non_printables[0], '\x00')
 
+    def test_get_qp_ctext_close_paren_only(self):
+        self._test_get_x(parser.get_qp_ctext,
+                        ')', '', ' ', [], ')')
+
+    def test_get_qp_ctext_open_paren_only(self):
+        self._test_get_x(parser.get_qp_ctext,
+                        '(', '', ' ', [], '(')
+
+    def test_get_qp_ctext_no_end_char(self):
+        self._test_get_x(parser.get_qp_ctext,
+                        '', '', ' ', [], '')
+
+
     # get_qcontent
 
     def test_get_qcontent_only(self):
@@ -503,6 +516,14 @@ class TestParser(TestParserMixin, TestEmailBase):
                                 [errors.NonPrintableDefect], '"')
         self.assertEqual(ptext.defects[0].non_printables[0], '\x00')
 
+    def test_get_qcontent_empty(self):
+        self._test_get_x(parser.get_qcontent,
+                         '"', '', '', [], '"')
+
+    def test_get_qcontent_no_end_char(self):
+        self._test_get_x(parser.get_qcontent,
+                         '', '', '', [], '')
+
     # get_atext
 
     def test_get_atext_only(self):
@@ -1283,6 +1304,18 @@ class TestParser(TestParserMixin, TestEmailBase):
         self._test_get_x(parser.get_dtext,
                         'foo[bar', 'foo', 'foo', [], '[bar')
 
+    def test_get_dtext_open_bracket_only(self):
+        self._test_get_x(parser.get_dtext,
+                        '[', '', '', [], '[')
+
+    def test_get_dtext_close_bracket_only(self):
+        self._test_get_x(parser.get_dtext,
+                        ']', '', '', [], ']')
+
+    def test_get_dtext_empty(self):
+        self._test_get_x(parser.get_dtext,
+                        '', '', '', [], '')
+
     # get_domain_literal
 
     def test_get_domain_literal_only(self):

diff --git a/Misc/NEWS.d/next/Library/2025-05-19-10-32-11.gh-issue-134152.INJC2j.rst b/Misc/NEWS.d/next/Library/2025-05-19-10-32-11.gh-issue-134152.INJC2j.rst
new file mode 100644 (file)
index 0000000..6da3d41
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-05-19-10-32-11.gh-issue-134152.INJC2j.rst
@@ -0,0 +1,2 @@
+Fixed :exc:`UnboundLocalError` that could occur during :mod:`email` header
+parsing if an expected trailing delimiter is missing in some contexts.