- Fixed a leak which would occur in the unsupported and highly

non-recommended use case of replacing a relationship on a fixed
mapped class many times, referring to an arbitrarily growing number of
target mappers.  A warning is emitted when the old relationship is
replaced, however if the mapping were already used for querying, the
old relationship would still be referenced within some registries.
fixes #3251

1 files changed, 26 insertions, 0 deletions

diff --git a/test/aaa_profiling/test_memusage.py b/test/aaa_profiling/test_memusage.py
index f4bce6b01..63883daac 100644
--- a/test/aaa_profiling/test_memusage.py
+++ b/test/aaa_profiling/test_memusage.py
@@ -658,6 +658,32 @@ class MemUsageTest(EnsureZeroed):
                 row[t.c.x]
         go()
 
+    def test_many_discarded_relationships(self):
+        """a use case that really isn't supported, nonetheless we can
+        guard against memleaks here so why not"""
+
+        m1 = MetaData()
+        t1 = Table('t1', m1, Column('id', Integer, primary_key=True))
+        t2 = Table(
+            't2', m1, Column('id', Integer, primary_key=True),
+            Column('t1id', ForeignKey('t1.id')))
+
+        class T1(object):
+            pass
+        t1_mapper = mapper(T1, t1)
+
+        @testing.emits_warning()
+        @profile_memory()
+        def go():
+            class T2(object):
+                pass
+            t2_mapper = mapper(T2, t2)
+            t1_mapper.add_property("bar", relationship(t2_mapper))
+            s1 = Session()
+            # this causes the path_registry to be invoked
+            s1.query(t1_mapper)._compile_context()
+        go()
+
     # fails on newer versions of pysqlite due to unusual memory behvior
     # in pysqlite itself. background at:
     # http://thread.gmane.org/gmane.comp.python.db.pysqlite.user/2290