From 50d229fe11d0da46dfa38e7943074d2cdf70d02b Mon Sep 17 00:00:00 2001
From: Keegan McAllister <keegan@humbughq.com>
Date: Wed, 2 Jan 2013 15:43:49 -0500
Subject: [PATCH] Accept '{}' to mean 'no narrowing', for old mobile clients

(imported from commit 879f6ef846f2a8980a0574372324d8dc8d22c8ed)
---
 zephyr/tests.py | 18 +++++++++++++++++-
 zephyr/views.py | 28 ++++++++++++++++------------
 2 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/zephyr/tests.py b/zephyr/tests.py
index 6d3fd6542d..5b0ed932ad 100644
--- a/zephyr/tests.py
+++ b/zephyr/tests.py
@@ -28,6 +28,9 @@ def find_key_by_email(address):
         if address in message.to:
             return key_regex.search(message.body).groups()[0]
 
+def message_ids(result):
+    return set(message['id'] for message in result['messages'])
+
 class AuthedTestCase(TestCase):
     def login(self, email, password=None):
         if password is None:
@@ -652,13 +655,26 @@ class GetOldMessagesTest(AuthedTestCase):
         other_params = [("anchor", 0), ("num_before", 0), ("num_after", 0)]
 
         bad_types = (False, 0, '', '{malformed json,',
-            '{}', '{foo: 3}', '[1,2]', '[["x","y","z"]]')
+            '{foo: 3}', '[1,2]', '[["x","y","z"]]')
         for type in bad_types:
             post_params = dict(other_params + [("narrow", type)])
             result = self.client.post("/json/get_old_messages", post_params)
             self.assert_json_error(result,
                                    "Bad value for 'narrow': %s" % (type,))
 
+    def test_old_empty_narrow(self):
+        """
+        '{}' is accepted to mean 'no narrow', for use by old mobile clients.
+        """
+        self.login("hamlet@humbughq.com")
+        all_result    = self.post_with_params({})
+        narrow_result = self.post_with_params({'narrow': '{}'})
+
+        for r in (all_result, narrow_result):
+            self.check_well_formed_messages_response(r)
+
+        self.assertEqual(message_ids(all_result), message_ids(narrow_result))
+
     def test_bad_narrow_operator(self):
         """
         Unrecognized narrow operators are rejected.
diff --git a/zephyr/views.py b/zephyr/views.py
index 9f89e42764..c5adf5a417 100644
--- a/zephyr/views.py
+++ b/zephyr/views.py
@@ -63,17 +63,6 @@ def json_to_list(json):
         raise ValueError("argument is not a list")
     return data
 
-def json_to_list_of_string_pairs(json):
-    data = json_to_list(json)
-    for elem in data:
-        if not isinstance(elem, list):
-            raise ValueError("element is not a list")
-        if (len(elem) != 2
-            or any(not isinstance(x, str) and not isinstance(x, unicode)
-                   for x in elem)):
-            raise ValueError("element is not a string pair")
-    return data
-
 def get_stream(stream_name, realm):
     try:
         return Stream.objects.get(name__iexact=stream_name, realm=realm)
@@ -347,11 +336,26 @@ class NarrowBuilder(object):
         return (Q(content__icontains=operand) |
                 Q(subject__icontains=operand))
 
+def narrow_parameter(json):
+    # FIXME: A hack to support old mobile clients
+    if json == '{}':
+        return None
+
+    data = json_to_list(json)
+    for elem in data:
+        if not isinstance(elem, list):
+            raise ValueError("element is not a list")
+        if (len(elem) != 2
+            or any(not isinstance(x, str) and not isinstance(x, unicode)
+                   for x in elem)):
+            raise ValueError("element is not a string pair")
+    return data
+
 @has_request_variables
 def get_old_messages_backend(request, anchor = POST(converter=to_non_negative_int),
                              num_before = POST(converter=to_non_negative_int),
                              num_after = POST(converter=to_non_negative_int),
-                             narrow = POST('narrow', converter=json_to_list_of_string_pairs, default=None),
+                             narrow = POST('narrow', converter=narrow_parameter, default=None),
                              user_profile=None, apply_markdown=True):
     query = Message.objects.select_related().filter(usermessage__user_profile = user_profile).order_by('id')