handle quotes in Content-Disposition filenames

Summary:
The HTTP standard specifies
(http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.5.1) that
`Content-Disposition` filenames can be quoted. I forgot to handle that.

Closes https://github.com/buildinspace/peru/issues/70.

Test Plan: Add a couple extra cases to the existing test.

Reviewers: sean

Reviewed By: sean

Differential Revision: https://phabricator.buildinspace.com/D144

peru/resources/plugins/curl/curl_plugin.py

@@ -16,7 +16,15 @@ def get_request_filename(request):
         pieces = re.split('\s*;\s*', disposition)
         for piece in pieces:
             if piece.startswith('filename='):
-                return piece[len('filename='):]
+                filename = piece[len('filename='):]
+                # Strip exactly one " from each end.
+                if filename.startswith('"'):
+                    filename = filename[1:]
+                if filename.endswith('"'):
+                    filename = filename[:-1]
+                # Interpret backslashed quotes.
+                filename = filename.replace('\\"', '"')
+                return filename
     # If no filename was specified, pick a reasonable default.
     return os.path.basename(urlsplit(request.url).path) or 'index.html'
 

tests/test_curl_plugin.py

@@ -46,6 +46,16 @@ class CurlPluginTest(unittest.TestCase):
                          'attachment; filename=bar'}
         self.assertEqual('bar',
                          curl_plugin.get_request_filename(request))
+        # Check quoted filenames.
+        request._info = {'Content-Disposition':
+                         'attachment; filename="bar"'}
+        self.assertEqual('bar',
+                         curl_plugin.get_request_filename(request))
+        # Check backslashed quotes in filenames.
+        request._info = {'Content-Disposition':
+                         'attachment; filename="bar\\""'}
+        self.assertEqual('bar"',
+                         curl_plugin.get_request_filename(request))
 
     def test_download_file_with_length(self):
         content = b'xy' * 4096