Fixed #10199 -- Modified aggregate() calls to clone the base query so that the base query can be reused. Thanks to Alex Gaynor for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9819 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -307,11 +307,13 @@ class QuerySet(object):
         for arg in args:
             kwargs[arg.default_alias] = arg
 
+        query = self.query.clone()
+
         for (alias, aggregate_expr) in kwargs.items():
-            self.query.add_aggregate(aggregate_expr, self.model, alias,
+            query.add_aggregate(aggregate_expr, self.model, alias,
                 is_summary=True)
 
-        return self.query.get_aggregation()
+        return query.get_aggregation()
 
     def count(self):
         """

tests/regressiontests/aggregation_regress/models.py

@@ -200,6 +200,12 @@ FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, conta
 >>> sorted([(b.name, b.authors__age__avg, b.publisher.name, b.contact.name) for b in books])
 [(u'Artificial Intelligence: A Modern Approach', 51.5, u'Prentice Hall', u'Peter Norvig'), (u'Practical Django Projects', 29.0, u'Apress', u'James Bennett'), (u'Python Web Development with Django', 30.3..., u'Prentice Hall', u'Jeffrey Forcier'), (u'Sams Teach Yourself Django in 24 Hours', 45.0, u'Sams', u'Brad Dayley')]
 
+# Regression for #10199 - Aggregate calls clone the original query so the original query can still be used
+>>> books = Book.objects.all()
+>>> _ = books.aggregate(Avg('authors__age'))
+>>> books.all()
+[<Book: Artificial Intelligence: A Modern Approach>, <Book: Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp>, <Book: Practical Django Projects>, <Book: Python Web Development with Django>, <Book: Sams Teach Yourself Django in 24 Hours>, <Book: The Definitive Guide to Django: Web Development Done Right>]
+
 """
 }