Content-Length enforcement fixups

Change-Id: Ice8144700cf447ecf5c6175dc64aa7662013fba5
Related-Change: I74d8c13eba2a4917b5a116875b51a781b33a7abf

swift/common/middleware/catch_errors.py

@@ -69,7 +69,6 @@ class CatchErrorsContext(WSGIContext):
 
         trans_id = generate_trans_id(trans_id_suffix)
         env['swift.trans_id'] = trans_id
-        method = env['REQUEST_METHOD']
         self.logger.txn_id = trans_id
         try:
             # catch any errors in the pipeline
@@ -101,7 +100,10 @@ class CatchErrorsContext(WSGIContext):
         # the socket. In that case, we truncate the response body at N bytes
         # and raise an exception to stop any more bytes from being
         # generated and also to kill the TCP connection.
-        if self._response_headers:
+        if env['REQUEST_METHOD'] == 'HEAD':
+            resp = enforce_byte_count(resp, 0)
+
+        elif self._response_headers:
             content_lengths = [val for header, val in self._response_headers
                                if header.lower() == "content-length"]
             if len(content_lengths) == 1:
@@ -110,9 +112,7 @@ class CatchErrorsContext(WSGIContext):
                 except ValueError:
                     pass
                 else:
-                    resp = enforce_byte_count(
-                        resp,
-                        0 if method == 'HEAD' else content_length)
+                    resp = enforce_byte_count(resp, content_length)
 
         # make sure the response has the trans_id
         if self._response_headers is None:

swift/common/middleware/dlo.py

@@ -155,7 +155,6 @@ class GetContext(WSGIContext):
         con_resp = con_req.get_response(self.dlo.app)
         if not is_success(con_resp.status_int):
             if req.method == 'HEAD':
-                close_if_possible(con_resp.app_iter)
                 con_resp.body = ''
             return con_resp, None
         with closing_if_possible(con_resp.app_iter):

swift/common/swob.py

@@ -316,6 +316,7 @@ def _resp_body_property():
             value = value.encode('utf-8')
         if isinstance(value, str):
             self.content_length = len(value)
+            close_if_possible(self._app_iter)
             self._app_iter = None
         self._body = value
 
@@ -400,6 +401,7 @@ def _resp_app_iter_property():
         elif value is not None:
             self.content_length = None
             self._body = None
+        close_if_possible(self._app_iter)
         self._app_iter = value
 
     return property(getter, setter,
@@ -1115,6 +1117,7 @@ class Response(object):
         self.conditional_response = conditional_response
         self._conditional_etag = conditional_etag
         self.request = request
+        self._app_iter = None
         self.body = body
         self.app_iter = app_iter
         self.response_iter = None