From 4c358df66a1c808dce09c9da634bb50969d18c37 Mon Sep 17 00:00:00 2001
From: Guillaume Pannatier <guillaume.pannatier@gmail.com>
Date: Thu, 29 May 2014 08:53:25 +0200
Subject: [PATCH] [1.6.x] Fixed #22710 -- Documented aggregation behavior for
 empty QuerySets.

Thanks matklad for the report.

Backport of 7c6e96ec1f from master
---
 docs/ref/models/querysets.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt
index dbca6b58060..1344c6744b6 100644
--- a/docs/ref/models/querysets.txt
+++ b/docs/ref/models/querysets.txt
@@ -2487,6 +2487,12 @@ aggregate functions, see
     aggregation on date/time fields in SQLite will raise
     ``NotImplementedError``.
 
+.. admonition:: Note
+
+    Aggregation functions will return ``None`` when used with an empty
+    ``QuerySet``. For example, the ``Count`` aggregation function will return
+    ``None`` instead of ``0`` if the ``QuerySet`` contains no entries.
+
 Avg
 ~~~