Cascade mappers in terms of the instance's mapper

Fixed a (extremely old) bug in cascade_mappers where the
first cascade we do is against the "self" mapper, and not the
one that actually corresponds to the state given. These are
different in the case where we start with a relationship
to a class, and the instance is of a subclass, which itself
can have relationships that aren't on the base mapper.

A pretty severe bug that somehow has avoided the radar
since the beginning.

Change-Id: I512956b9757b07e06f3ca1ccb507a33fb10bed31
Fixes: #3986

diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst
index c591b483f753dc5fcc3c52e87addec0e6e0b24b7..523b66f82e298d0fb491220a8711df55d265537c 100644 (file)
--- a/doc/build/changelog/changelog_11.rst
+++ b/doc/build/changelog/changelog_11.rst
@@ -21,6 +21,16 @@
 .. changelog::
     :version: 1.1.10
 
+    .. change:: 3986
+        :tags: bug, orm
+        :versions: 1.2.0b1
+        :tickets: 3986
+
+        Fixed bug where a cascade such as "delete-orphan" (but others as well)
+        would fail to locate an object linked to a relationship that itself
+        is local to a subclass in an inheritance relationship, thus causing
+        the operation to not take place.
+
     .. change:: 3975
         :tags: bug, oracle
         :versions: 1.2.0b1

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index 3fdba44825ecfdf05135f897e463a84c9b25a615..61a9290c4cf4a7a532cee9731505c1852d64519c 100644 (file)
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -2689,7 +2689,9 @@ class Mapper(InspectionAttr):
         visited_states = set()
         prp, mpp = object(), object()
 
-        visitables = deque([(deque(self._props.values()), prp,
+        assert state.mapper.isa(self)
+
+        visitables = deque([(deque(state.mapper._props.values()), prp,
                              state, state.dict)])
 
         while visitables:
@@ -2712,9 +2714,13 @@ class Mapper(InspectionAttr):
                     corresponding_dict = iterator.popleft()
                 yield instance, instance_mapper, \
                     corresponding_state, corresponding_dict
-                visitables.append((deque(instance_mapper._props.values()),
-                                   prp, corresponding_state,
-                                   corresponding_dict))
+                visitables.append(
+                    (
+                        deque(instance_mapper._props.values()),
+                        prp, corresponding_state,
+                        corresponding_dict
+                    )
+                )
 
     @_memoized_configured_property
     def _compiled_cache(self):

diff --git a/test/orm/test_cascade.py b/test/orm/test_cascade.py
index f660321c24f28928d10851228ebdf3d59f0d2a99..55467db4b9b9b93a21eb6c5c8e8d50eb897da5f8 100644 (file)
--- a/test/orm/test_cascade.py
+++ b/test/orm/test_cascade.py
@@ -3067,3 +3067,142 @@ class PartialFlushTest(fixtures.MappedTest):
         assert p1 in sess.new
         assert c1 not in sess.new
         assert c2 in sess.new
+
+
+class SubclassCascadeTest(fixtures.DeclarativeMappedTest):
+    @classmethod
+    def setup_classes(cls):
+        Base = cls.DeclarativeBasic
+
+        class Company(Base):
+            __tablename__ = 'company'
+            id = Column(Integer, primary_key=True)
+            name = Column(String(50))
+            employees = relationship("Employee", cascade="all, delete-orphan")
+
+        class Employee(Base):
+            __tablename__ = 'employee'
+            id = Column(Integer, primary_key=True)
+            name = Column(String(50))
+            type = Column(String(50))
+            company_id = Column(ForeignKey('company.id'))
+
+            __mapper_args__ = {
+                'polymorphic_identity': 'employee',
+                'polymorphic_on': type
+            }
+
+        class Engineer(Employee):
+            __tablename__ = 'engineer'
+            id = Column(Integer, ForeignKey('employee.id'), primary_key=True)
+            engineer_name = Column(String(30))
+            languages = relationship("Language", cascade="all, delete-orphan")
+
+            __mapper_args__ = {
+                'polymorphic_identity': 'engineer',
+            }
+
+        class MavenBuild(Base):
+            __tablename__ = 'maven_build'
+            id = Column(Integer, primary_key=True)
+            java_language_id = Column(
+                ForeignKey('java_language.id'), nullable=False)
+
+        class Manager(Employee):
+            __tablename__ = 'manager'
+            id = Column(Integer, ForeignKey('employee.id'), primary_key=True)
+            manager_name = Column(String(30))
+
+            __mapper_args__ = {
+                'polymorphic_identity': 'manager',
+            }
+
+        class Language(Base):
+            __tablename__ = 'language'
+            id = Column(Integer, primary_key=True)
+            engineer_id = Column(ForeignKey('engineer.id'), nullable=False)
+            name = Column(String(50))
+            type = Column(String(50))
+
+            __mapper_args__ = {
+                "polymorphic_on": type,
+                "polymorphic_identity": "language"
+            }
+
+        class JavaLanguage(Language):
+            __tablename__ = 'java_language'
+            id = Column(ForeignKey('language.id'), primary_key=True)
+            maven_builds = relationship("MavenBuild",
+                                        cascade="all, delete-orphan")
+
+            __mapper_args__ = {
+                "polymorphic_identity": "java_language"
+            }
+
+    def test_cascade_iterator_polymorphic(self):
+        Company, Employee, Engineer, Language, JavaLanguage, MavenBuild = \
+        self.classes(
+            'Company', 'Employee', 'Engineer', 'Language', 'JavaLanguage',
+            'MavenBuild'
+        )
+
+        obj = Company(
+            employees=[
+                Engineer(
+                    languages=[
+                        JavaLanguage(
+                            name="java",
+                            maven_builds=[MavenBuild()]
+                        )
+                    ],
+
+                )
+            ]
+        )
+        eng = obj.employees[0]
+        lang = eng.languages[0]
+        maven_build = lang.maven_builds[0]
+
+        from sqlalchemy import inspect
+        state = inspect(obj)
+        it = inspect(Company).cascade_iterator("save-update", state)
+        eq_(
+            set([rec[0] for rec in it]),
+            set([eng, maven_build, lang])
+        )
+
+        state = inspect(eng)
+        it = inspect(Employee).cascade_iterator("save-update", state)
+        eq_(
+            set([rec[0] for rec in it]),
+            set([maven_build, lang])
+        )
+
+    def test_delete_orphan_round_trip(self):
+        Company, Employee, Engineer, Language, JavaLanguage, \
+            MavenBuild = self.classes(
+                'Company', 'Employee', 'Engineer', 'Language', 'JavaLanguage',
+                'MavenBuild'
+            )
+
+        obj = Company(
+            employees=[
+                Engineer(
+                    languages=[
+                        JavaLanguage(
+                            name="java",
+                            maven_builds=[MavenBuild()]
+                        )
+                    ],
+
+                )
+            ]
+        )
+        s = Session()
+        s.add(obj)
+        s.commit()
+
+        obj.employees = []
+        s.commit()
+
+        eq_(s.query(Language).count(), 0)
\ No newline at end of file