[gtk-doc] mkdb: ensure deterministic index files.

[Stefan Sauer <stefkost src gnome org>]

commit 51762cfe2b47c886558ee5b311dca24bd5ddcd83
Author: Stefan Sauer <ensonic users sf net>
Date:   Mon Dec 23 12:23:41 2019 +0100

    mkdb: ensure deterministic index files.

 gtkdoc/mkdb.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtkdoc/mkdb.py b/gtkdoc/mkdb.py
index 9184567..87fdf24 100644
--- a/gtkdoc/mkdb.py
+++ b/gtkdoc/mkdb.py
@@ -969,7 +969,7 @@ def OutputIndex(basename, apiindex):
 
 def OutputSinceIndexes():
     """Generate the 'since' api index files."""
-    for version in set(Since.values()):
+    for version in sorted(set(Since.values())):
         logging.info("Since : [%s]", version)
         index = {x: IndexEntriesSince[x] for x in IndexEntriesSince.keys() if Since[x] == version}
         OutputIndex("api-index-" + version, index)