Close #7220: genindex: Show "main" index entries at first

1 files changed, 12 insertions, 3 deletions

diff --git a/sphinx/environment/adapters/indexentries.py b/sphinx/environment/adapters/indexentries.py
index 1d135bd32..dbc94f846 100644
--- a/sphinx/environment/adapters/indexentries.py
+++ b/sphinx/environment/adapters/indexentries.py
@@ -7,7 +7,7 @@
     :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
-import bisect
+
 import re
 import unicodedata
 from itertools import groupby
@@ -52,8 +52,7 @@ class IndexEntries:
                 except NoUri:
                     pass
                 else:
-                    # maintain links in sorted/deterministic order
-                    bisect.insort(entry[0], (main, uri))
+                    entry[0].append((main, uri))
 
         domain = cast(IndexDomain, self.env.get_domain('index'))
         for fn, entries in domain.entries.items():
@@ -89,6 +88,16 @@ class IndexEntries:
                 except ValueError as err:
                     logger.warning(str(err), location=fn)
 
+        # sort the index entries for same keyword.
+        def keyfunc0(entry: Tuple[str, str]) -> Tuple[bool, str]:
+            main, uri = entry
+            return (not main, uri)  # show main entries at first
+
+        for indexentry in new.values():
+            indexentry[0] = sorted(indexentry[0], key=keyfunc0)
+            for subentry in indexentry[1].values():
+                subentry[0] = sorted(subentry[0], key=keyfunc0)  # type: ignore
+
         # 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: Tuple[str, List]) -> Tuple[str, str]: