Fix Python 3 issues in REST code.

* Need to use .get not .getheader for HTTP headers (see hg commit
  fec18298ae02, "Python 3 preparation: HTTP headers handling in
  roundup_server.py.").

* Need to use key not cmp with sort (see hg commit 3fa026621f69,
  "Python 3 preparation: comparisons.").

* dispatch output must be bytes, not str, otherwise writing it to the
  socket (e.g. in roundup-server) will fail.

This fixes issues shown up attempting to access the REST interface
with a browser with Python 3 (as opposed to with the Roundup
testsuite, which also has known REST issues with Python 3).

Author: jsm28

roundup/rest.py

@@ -27,7 +27,7 @@
 from roundup import hyperdb
 from roundup import date
 from roundup import actions
-from roundup.anypy.strings import bs2b
+from roundup.anypy.strings import bs2b, s2b
 from roundup.exceptions import *
 from roundup.cgi.exceptions import *
 
@@ -160,7 +160,7 @@ def obtain_etags(headers,input):
     etags = []
     if '@etag' in input:
         etags.append(input['@etag'].value);
-    etags.append(headers.getheader("ETag", None))
+    etags.append(headers.get("ETag", None))
     return etags
 
 def parse_accept_header(accept):
@@ -220,7 +220,7 @@ def parse_accept_header(accept):
             else:
                 media_params.append((key, value))
         result.append((media_type, dict(media_params), q))
-    result.sort(lambda x, y: -cmp(x[2], y[2]))
+    result.sort(key=lambda x: x[2], reverse=True)
     return result
 
 
@@ -1299,7 +1299,7 @@ def dispatch(self, method, uri, input):
         headers = self.client.request.headers
         # Never allow GET to be an unsafe operation (i.e. data changing).
         # User must use POST to "tunnel" DELETE, PUT, OPTIONS etc.
-        override = headers.getheader('X-HTTP-Method-Override')
+        override = headers.get('X-HTTP-Method-Override')
         output = None
         if override:
             if method.upper() != 'GET':
@@ -1314,7 +1314,7 @@ def dispatch(self, method, uri, input):
                     uri)
 
         # parse Accept header and get the content type
-        accept_header = parse_accept_header(headers.getheader('Accept'))
+        accept_header = parse_accept_header(headers.get('Accept'))
         accept_type = "invalid"
         for part in accept_header:
             if part[0] in self.__accepted_content_type:
@@ -1350,7 +1350,7 @@ def dispatch(self, method, uri, input):
         # Is there an input.value with format json data?
         # If so turn it into an object that emulates enough
         # of the FieldStorge methods/props to allow a response.
-        content_type_header = headers.getheader('Content-Type', None)
+        content_type_header = headers.get('Content-Type', None)
         if type(input.value) == str and content_type_header:
             parsed_content_type_header = content_type_header
             # the structure of a content-type header
@@ -1404,7 +1404,7 @@ def dispatch(self, method, uri, input):
 
         # Make output json end in a newline to
         # separate from following text in logs etc..
-        return output + "\n"
+        return s2b(output + "\n")
 
 
 class RoundupJSONEncoder(json.JSONEncoder):

test/rest_common.py

@@ -68,7 +68,7 @@ def setUp(self):
             'TRACKER_NAME': 'rounduptest'
         }
         self.dummy_client = client.Client(self.instance, MockNull(), env, [], None)
-        self.dummy_client.request.headers.getheader = self.get_header
+        self.dummy_client.request.headers.get = self.get_header
         self.empty_form = cgi.FieldStorage()
 
         self.server = RestfulInstance(self.dummy_client, self.db)
@@ -426,7 +426,7 @@ def testDispatch(self):
         form = cgi.FieldStorage(body_file,
                                 headers=headers,
                                 environ=env)
-        self.server.client.request.headers.getheader=self.get_header
+        self.server.client.request.headers.get=self.get_header
         results = self.server.dispatch('PUT',
                             "/rest/data/user/%s/realname"%self.joeid,
                             form)
@@ -455,7 +455,7 @@ def testDispatch(self):
         form = cgi.FieldStorage(body_file,
                                 headers=headers,
                                 environ=env)
-        self.server.client.request.headers.getheader=self.get_header
+        self.server.client.request.headers.get=self.get_header
         results = self.server.dispatch('PUT',
                             "/rest/data/user/%s/realname"%self.joeid,
                             form)
@@ -483,7 +483,7 @@ def testDispatch(self):
             cgi.MiniFieldStorage('data', 'Joe Doe'),
         ]
         self.headers = headers
-        self.server.client.request.headers.getheader = self.get_header
+        self.server.client.request.headers.get = self.get_header
         results = self.server.dispatch('PUT',
                             "/rest/data/user/%s/realname"%self.joeid,
                             form)
@@ -523,7 +523,7 @@ def testDispatch(self):
         form = cgi.FieldStorage(body_file,
                                 headers=headers,
                                 environ=env)
-        self.server.client.request.headers.getheader=self.get_header
+        self.server.client.request.headers.get=self.get_header
         results = self.server.dispatch('PATCH',
                             "/rest/data/user/%s"%self.joeid,
                             form)
@@ -544,7 +544,7 @@ def testDispatch(self):
         form = cgi.FieldStorage(body_file,
                                 headers=headers,
                                 environ=env)
-        self.server.client.request.headers.getheader=self.get_header
+        self.server.client.request.headers.get=self.get_header
         results = self.server.dispatch('PATCH',
                             "/rest/data/user/%s"%self.joeid,
                             form)
@@ -571,7 +571,7 @@ def testDispatch(self):
         form = cgi.FieldStorage(body_file,
                                 headers=headers,
                                 environ=env)
-        self.server.client.request.headers.getheader=self.get_header
+        self.server.client.request.headers.get=self.get_header
         results = self.server.dispatch('POST',
                             "/rest/data/issue",
                             form)