Don't send body in response to HEAD request

aiohttp/web_reqrep.py

@@ -851,11 +851,15 @@ def text(self, text):
 
         self.body = text.encode(self.charset)
 
+    def should_send_body(self):
+        return (self._req.method.lower() != 'head' and
+                self._status not in [204, 304])
+
     @asyncio.coroutine
     def write_eof(self):
         try:
             body = self._body
-            if body is not None:
+            if body is not None and self.should_send_body():
                 self.write(body)
         finally:
             self.set_tcp_nodelay(True)

tests/test_web_functional.py

@@ -98,6 +98,32 @@ def go():
         self.loop.run_until_complete(go())
         logger.exception.assert_called_with("Error handling request")
 
+    def test_head_returns_empty_body(self):
+
+        @asyncio.coroutine
+        def handler(request):
+            body = yield from request.read()
+            self.assertEqual(b'', body)
+            return web.Response(body=b'test')
+
+        @asyncio.coroutine
+        def go():
+            _, _, url = yield from self.create_server('HEAD', '/', handler)
+            with ClientSession(loop=self.loop) as session:
+                resp = yield from session.head(url, version=HttpVersion11)
+                self.assertEqual(200, resp.status)
+                txt = yield from resp.text()
+                self.assertEqual('', txt)
+                resp.close()
+
+                resp = yield from session.head(url, version=HttpVersion11)
+                self.assertEqual(200, resp.status)
+                txt = yield from resp.text()
+                self.assertEqual('', txt)
+                resp.close()
+
+        self.loop.run_until_complete(go())
+
     def test_post_form(self):
 
         @asyncio.coroutine