From b0308a7b3af91cc61fbe3347376024ad8b7be019 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sun, 29 Nov 2015 11:42:55 -0500
Subject: [PATCH] - Fixed an issue in baked queries where the .get() method,
 used either directly or within lazy loads, didn't consider the mapper's "get
 clause" as part of the cache key, causing bound parameter mismatches if the
 clause got re-generated.  This clause is cached by mappers on the fly but in
 highly concurrent scenarios may be generated more than once when first
 accessed. fixes #3597

---
 doc/build/changelog/changelog_10.rst | 12 ++++++++++++
 lib/sqlalchemy/ext/baked.py          |  6 ++++++
 test/ext/test_baked.py               | 24 ++++++++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/doc/build/changelog/changelog_10.rst b/doc/build/changelog/changelog_10.rst
index 7e289a526b..8d6dcd2a99 100644
--- a/doc/build/changelog/changelog_10.rst
+++ b/doc/build/changelog/changelog_10.rst
@@ -18,6 +18,18 @@
 .. changelog::
     :version: 1.0.10
 
+    .. change::
+        :tags: bug, ext
+        :versions: 1.1.0b1
+        :tickets: 3597
+
+        Fixed an issue in baked queries where the .get() method, used either
+        directly or within lazy loads, didn't consider the mapper's "get clause"
+        as part of the cache key, causing bound parameter mismatches if the
+        clause got re-generated.  This clause is cached by mappers
+        on the fly but in highly concurrent scenarios may be generated more
+        than once when first accessed.
+
     .. change::
         :tags: feature, sql
         :versions: 1.1.0b1
diff --git a/lib/sqlalchemy/ext/baked.py b/lib/sqlalchemy/ext/baked.py
index ee9f6f9bbc..eb0c36805e 100644
--- a/lib/sqlalchemy/ext/baked.py
+++ b/lib/sqlalchemy/ext/baked.py
@@ -354,6 +354,12 @@ class Result(object):
         # (remember, we can map to an OUTER JOIN)
         bq = self.bq
 
+        # add the clause we got from mapper._get_clause to the cache
+        # key so that if a race causes multiple calls to _get_clause,
+        # we've cached on ours
+        bq = bq._clone()
+        bq._cache_key += (_get_clause, )
+
         bq = bq.with_criteria(setup, tuple(elem is None for elem in ident))
 
         params = dict([
diff --git a/test/ext/test_baked.py b/test/ext/test_baked.py
index dcf333184c..7004358fcf 100644
--- a/test/ext/test_baked.py
+++ b/test/ext/test_baked.py
@@ -271,6 +271,30 @@ class LikeQueryTest(BakedTest):
             eq_(u2.name, 'chuck')
         self.assert_sql_count(testing.db, go, 0)
 
+    def test_get_includes_getclause(self):
+        # test issue #3597
+        User = self.classes.User
+
+        bq = self.bakery(lambda s: s.query(User))
+
+        for i in range(5):
+            sess = Session()
+            u1 = bq(sess).get(7)
+            eq_(u1.name, 'jack')
+
+        eq_(len(bq._bakery), 2)
+
+        # simulate race where mapper._get_clause
+        # may be generated more than once
+        from sqlalchemy import inspect
+        del inspect(User).__dict__['_get_clause']
+
+        for i in range(5):
+            sess = Session()
+            u1 = bq(sess).get(7)
+            eq_(u1.name, 'jack')
+        eq_(len(bq._bakery), 4)
+
 
 class ResultTest(BakedTest):
     __backend__ = True
-- 
2.47.2