Fix #3183: Randomized jump box order in generated index page.

2 files changed, 6 insertions, 2 deletions

diff --git a/CHANGES b/CHANGES
index 8e73f560a..750dda19f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -23,7 +23,7 @@ Bugs fixed
 * #3228: ``build_sphinx`` command crashes when missing dependency
 * #2469: Ignore updates of catalog files for gettext builder. Thanks to
   Hiroshi Ohkubo.
-
+* #3183: Randomized jump box order in generated index page.
 
 Release 1.5 (released Dec 5, 2016)
 ==================================
diff --git a/sphinx/environment/managers/indexentries.py b/sphinx/environment/managers/indexentries.py
index c35a161b4..d4e5f05bd 100644
--- a/sphinx/environment/managers/indexentries.py
+++ b/sphinx/environment/managers/indexentries.py
@@ -115,7 +115,11 @@ class IndexEntries(EnvironmentManager):
         # sort the index entries; put all symbols at the front, even those
         # following the letters in ASCII, this is where the chr(127) comes from
         def keyfunc(entry, lcletters=string.ascii_lowercase + '_'):
-            lckey = unicodedata.normalize('NFD', entry[0].lower())
+            key, (void, void, category_key) = entry
+            if category_key:
+                # using specified category key to sort
+                key = category_key
+            lckey = unicodedata.normalize('NFD', key.lower())
             if lckey[0:1] in lcletters:
                 lckey = chr(127) + lckey
             # ensure a determinstic order *within* letters by also sorting on