1 files changed, 23 insertions, 0 deletions
diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
index cb28aa8..0a1e8d3 100644
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -256,6 +256,29 @@ class CgiTests(unittest.TestCase):
                     got = getattr(fs.list[x], k)
                     self.assertEqual(got, exp)
 
+    def test_fieldstorage_multipart_maxline(self):
+        # Issue #18167
+        maxline = 1 << 16
+        self.maxDiff = None
+        def check(content):
+            data = """---123
+Content-Disposition: form-data; name="upload"; filename="fake.txt"
+Content-Type: text/plain
+
+%s
+---123--
+""".replace('\n', '\r\n') % content
+            environ = {
+                'CONTENT_LENGTH':   str(len(data)),
+                'CONTENT_TYPE':     'multipart/form-data; boundary=-123',
+                'REQUEST_METHOD':   'POST',
+            }
+            self.assertEqual(gen_result(data, environ),
+                             {'upload': content.encode('latin1')})
+        check('x' * (maxline - 1))
+        check('x' * (maxline - 1) + '\r')
+        check('x' * (maxline - 1) + '\r' + 'y' * (maxline - 1))
+
     _qs_result = {
         'key1': 'value1',
         'key2': ['value2x', 'value2y'],