Do not use the gzipped file to compute the ETag.

mojo/devtools/common/devtoolslib/http_server.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import atexit
 import datetime
 import email.utils
 import errno
 import gzip
 import hashlib
@@ skipping 56 matching lines @@
     """
 
     def __init__(self, *args, **kwargs):
       self.etag = None
       SimpleHTTPServer.SimpleHTTPRequestHandler.__init__(self, *args, **kwargs)
 
     def get_etag(self):
       if self.etag:
         return self.etag
 
-      path = self.translate_path(self.path)
+      path = self.translate_path(self.path, False)
       if not os.path.isfile(path):
         return None
 
       sha256 = hashlib.sha256()
       BLOCKSIZE = 65536
       with open(path, 'rb') as hashed:
         buf = hashed.read(BLOCKSIZE)
         while len(buf) > 0:
           sha256.update(buf)
           buf = hashed.read(BLOCKSIZE)
@@ skipping 35 matching lines @@
 
       if os.path.isfile(path):
         self.send_header('Content-Encoding', 'gzip')
         etag = self.get_etag()
         if etag:
           self.send_header('ETag', etag)
           self.send_header('Cache-Control', 'must-revalidate')
 
       return SimpleHTTPServer.SimpleHTTPRequestHandler.end_headers(self)
 
-    def translate_path(self, path):
+    # pylint: disable=W0221
+    def translate_path(self, path, gzipped=True):
       # Parent translate_path() will strip away the query string and fragment
       # identifier, but also will prepend the cwd to the path. relpath() gives
       # us the relative path back.
       normalized_path = os.path.relpath(
           SimpleHTTPServer.SimpleHTTPRequestHandler.translate_path(self, path))
 
       for prefix, local_base_path in mappings:
         if normalized_path.startswith(prefix):
           result = os.path.join(local_base_path, normalized_path[len(prefix):])
           if os.path.isfile(result):
-            gz_result = result + '.gz'
-            if (not os.path.isfile(gz_result) or
-                os.path.getmtime(gz_result) <= os.path.getmtime(result)):
-              with open(result, 'rb') as f:
-                with gzip.open(gz_result, 'wb') as zf:
-                  shutil.copyfileobj(f, zf)
-            result = gz_result
+            if gzipped:
+              gz_result = result + '.gz'
+              if (not os.path.isfile(gz_result) or
+                  os.path.getmtime(gz_result) <= os.path.getmtime(result)):
+                with open(result, 'rb') as f:
+                  with gzip.open(gz_result, 'wb') as zf:
+                    shutil.copyfileobj(f, zf)
+              result = gz_result
           return result
 
       # This class is only used internally, and we're adding a catch-all ''
       # prefix at the end of |mappings|.
       assert False
 
     def guess_type(self, path):
       # This is needed so that exploded Sky apps without shebang can still run
       # thanks to content-type mappings.
       # TODO(ppi): drop this part once we can rely on the Sky files declaring
@@ skipping 43 matching lines @@
     return httpd.server_address
   except socket.error as v:
     error_code = v[0]
     print 'Failed to start http server for %s on port %d: %s.' % (
         local_dir_path, host_port, os.strerror(error_code))
     if error_code == errno.EADDRINUSE:
       print ('  Run `fuser %d/tcp` to find out which process is using the port.'
              % host_port)
     print '---'
     raise