bpo-40597: Allow email.contextmanager set_content() to set a null string. (GH-20542)

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/test/test_email/test_contentmanager.py b/Lib/test/test_email/test_contentmanager.py
index 64dca2d..f4f6bb7 100644
--- a/Lib/test/test_email/test_contentmanager.py
+++ b/Lib/test/test_email/test_contentmanager.py
@@ -303,6 +303,19 @@ class TestRawDataManager(TestEmailBase):
         self.assertEqual(m.get_payload(decode=True).decode('utf-8'), content)
         self.assertEqual(m.get_content(), content)
 
+    def test_set_text_plain_null(self):
+        m = self._make_message()
+        content = ''
+        raw_data_manager.set_content(m, content)
+        self.assertEqual(str(m), textwrap.dedent("""\
+            Content-Type: text/plain; charset="utf-8"
+            Content-Transfer-Encoding: 7bit
+
+
+            """))
+        self.assertEqual(m.get_payload(decode=True).decode('utf-8'), '\n')
+        self.assertEqual(m.get_content(), '\n')
+
     def test_set_text_html(self):
         m = self._make_message()
         content = "<p>Simple message.</p>\n"