Randomize scores of all top level comments for shuffle sort

This will ensure that all top level comments are considered for
display. It also makes it more clear that the sorting of child
comments is uneffected.

r2/r2/models/builder.py

@@ -50,7 +50,6 @@
 from r2.lib.jsontemplates import get_trimmed_sr_dicts
 from r2.lib.utils import (
     long_datetime,
-    shuffle_slice,
     SimpleSillyStub,
     Storage,
     to36,
@@ -847,6 +846,15 @@ def get_comment_order(self):
                 self.link, sort_name, comment_tree.cids, comment_tree_timer)
             comment_tree_timer.intermediate('get_scores')
 
+        if isinstance(self.sort, operators.shuffled):
+            # randomize the scores of top level comments
+            top_level_ids = comment_tree.tree.get(None, [])
+            top_level_scores = [
+                sorter[comment_id] for comment_id in top_level_ids]
+            shuffle(top_level_scores)
+            for i, comment_id in enumerate(top_level_ids):
+                sorter[comment_id] = top_level_scores[i]
+
         self.timer.intermediate("load_storage")
 
         comment_tree = self.modify_comment_tree(comment_tree)
@@ -1482,14 +1490,6 @@ def _make_wrapped_tree(self):
 
         self.timer.intermediate("build_comments")
 
-        if isinstance(self.sort, operators.shuffled):
-            # If we have a sticky comment, do not shuffle the first element
-            # of the list.
-            if len(final) > 0 and final[0]._id == self.link.sticky_comment_id:
-                shuffle_slice(final, 1)
-            else:
-                shuffle(final)
-
         if not self.load_more:
             timer.stop()
             return final