Fix header name parsing, if name is split into multiple lines #2183

aiohttp/_http_parser.pyx

@@ -137,9 +137,16 @@ cdef class HttpParser:
             self._raw_headers.append((raw_name, raw_value))
 
     cdef _on_header_field(self, str field, bytes raw_field):
-        self._process_header()
-        self._header_name = field
-        self._raw_header_name = raw_field
+        if self._header_value is not None:
+            self._process_header()
+            self._header_value = None
+
+        if self._header_name is None:
+            self._header_name = field
+            self._raw_header_name = raw_field
+        else:
+            self._header_name += field
+            self._raw_header_name += raw_field
 
     cdef _on_header_value(self, str val, bytes raw_val):
         if self._header_value is None:

changes/2183.bugfix

@@ -0,0 +1 @@
+Fix header name parsing, if name is split into multiple lines

tests/test_http_parser.py

@@ -141,6 +141,27 @@ def test_headers_multi_feed(parser):
     assert not msg.upgrade
 
 
+def test_headers_split_field(parser):
+    text1 = b'GET /test HTTP/1.1\r\n'
+    text2 = b't'
+    text3 = b'es'
+    text4 = b't: value\r\n\r\n'
+
+    messages, upgrade, tail = parser.feed_data(text1)
+    messages, upgrade, tail = parser.feed_data(text2)
+    messages, upgrade, tail = parser.feed_data(text3)
+    assert len(messages) == 0
+    messages, upgrade, tail = parser.feed_data(text4)
+    assert len(messages) == 1
+
+    msg = messages[0][0]
+    assert list(msg.headers.items()) == [('test', 'value')]
+    assert msg.raw_headers == ((b'test', b'value'),)
+    assert not msg.should_close
+    assert msg.compression is None
+    assert not msg.upgrade
+
+
 def test_parse_headers_multi(parser):
     text = (b'GET /test HTTP/1.1\r\n'
             b'Set-Cookie: c1=cookie1\r\n'