Fixed #26706 -- Made RelatedManager modification methods clear prefetch_related() cache.

2 files changed, 20 insertions, 0 deletions

diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt
index 36d791db0e..3f4fce1a26 100644
--- a/docs/ref/models/querysets.txt
+++ b/docs/ref/models/querysets.txt
@@ -979,6 +979,18 @@ database.
     performance, since you have done a database query that you haven't used. So
     use this feature with caution!
 
+    Also, if you call the database-altering methods
+    :meth:`~django.db.models.fields.related.RelatedManager.add`,
+    :meth:`~django.db.models.fields.related.RelatedManager.remove`,
+    :meth:`~django.db.models.fields.related.RelatedManager.clear` or
+    :meth:`~django.db.models.fields.related.RelatedManager.set`, on
+    :class:`related managers<django.db.models.fields.related.RelatedManager>`,
+    any prefetched cache for the relation will be cleared.
+
+    .. versionchanged:: 1.11
+
+        The clearing of the prefetched cache described above was added.
+
 You can also use the normal join syntax to do related fields of related
 fields. Suppose we have an additional model to the example above::
 
diff --git a/docs/ref/models/relations.txt b/docs/ref/models/relations.txt
index d8100287df..c34d3104b2 100644
--- a/docs/ref/models/relations.txt
+++ b/docs/ref/models/relations.txt
@@ -170,6 +170,14 @@ Related objects reference
        ``add()``, ``create()``, ``remove()``, and ``set()`` methods are
        disabled.
 
+       If you use :meth:`~django.db.models.query.QuerySet.prefetch_related`,
+       the ``add()``, ``remove()``, ``clear()``, and ``set()`` methods clear
+       the prefetched cache.
+
+       .. versionchanged:: 1.11
+
+            The clearing of the prefetched cache described above was added.
+
 Direct Assignment
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