Fix pagination problems with search.

This is a cherry pick of d03353c backported to next.

* Paginating wasn't working correctly for questios or forum post search
  results.  The pages would get generated, but all results would be
  shown on every page.  A typo was preventing the question_s and
  discussion_s from picking up the sliced s.
* Also, this changes type_ to kind so it's less built-inny
* Quoting the comment I modified and added to:

  If we're doing elasticsearch, then we need to update
  the _s variables to point to the sliced versions of
  S so that, when we iterate over them in the
  following list comp, we hang onto the version that
  does the query, so we can call excerpt() on it
  later.

  We only need to do this with elasticsearch.  For Sphinx,
  search_s at this point is an ObjectResults and not an S
  because we've already acquired object_ids on it.  Thus
  if we update the _s variables, we'd be pointing to the
  ObjectResults and not the S and then excerpting breaks.

* This tests that excerpting works for elasticsearch.  If it works then
  it means that we're excerpting with the same S that we did the query
  with.

apps/questions/tests/test_es.py

@@ -1,11 +1,11 @@
 import uuid
+import json
 
 import elasticutils
 from nose.tools import eq_
 
-from questions.tests import ESTestCase
 from questions.models import Question, Answer
-from sumo.tests import LocalizingClient
+from questions.tests import ESTestCase
 from sumo.urlresolvers import reverse
 
 

apps/search/views.py

@@ -277,30 +277,43 @@ def search(request, template=None):
             documents_dict.setdefault(doc[0], []).append(doc[1][0])
 
         docs_for_page = []
-        for type_, search_s in [('wiki', wiki_s),
+        for kind, search_s in [('wiki', wiki_s),
                                 ('question', question_s),
                                 ('discussion', discussion_s)]:
-            if type_ not in documents_dict:
+            if kind not in documents_dict:
                 continue
 
             # documents_dict[type_] is a list of indexes--one for each
             # object id search result for that type_.  We use the values
             # at the beginning and end of the list for slice boundaries.
-            begin = documents_dict[type_][0]
-            end = documents_dict[type_][-1] + 1
-
-            # Update the original symbols with the sliced versions of
-            # the S so that, when we iterate over them in the
-            # following list comp, we hang onto the version that does
-            # the query, so we can call excerpt() on it later.
-            if type_ == 'wiki':
-                wiki_s = search_s = search_s[begin:end]
-            elif type == 'question':
-                question_s = search_s = search_s[begin:end]
-            elif type == 'discussion':
-                discussion_s = search_s = search_s[begin:end]
-
-            docs_for_page += [(type_, doc) for doc in search_s]
+            begin = documents_dict[kind][0]
+            end = documents_dict[kind][-1] + 1
+
+            search_s = search_s[begin:end]
+
+            if waffle.flag_is_active(request, 'elasticsearch'):
+                # If we're doing elasticsearch, then we need to update
+                # the _s variables to point to the sliced versions of
+                # S so that, when we iterate over them in the
+                # following list comp, we hang onto the version that
+                # does the query, so we can call excerpt() on it
+                # later.
+                #
+                # We only need to do this with elasticsearch.  For Sphinx,
+                # search_s at this point is an ObjectResults and not an S
+                # because we've already acquired object_ids on it.  Thus
+                # if we update the _s variables, we'd be pointing to the
+                # ObjectResults and not the S and then excerpting breaks.
+                #
+                # Ugh.
+                if kind == 'wiki':
+                    wiki_s = search_s
+                elif kind == 'question':
+                    question_s = search_s
+                elif kind == 'discussion':
+                    discussion_s = search_s
+
+            docs_for_page += [(kind, doc) for doc in search_s]
 
         results = []
         for i, docinfo in enumerate(docs_for_page):