Propagate hybrid properties / info

Keystone and others depend on the .property attribute being
"mirrored" when a @hybrid_property is linked directly to a
mapped attribute.  Restore this linkage and also create a defined
behavior for the .info dictionary; it is that of the hybrid itself.
Add this behavioral change to the migration notes.

Change-Id: I8ac34ef52039387230c648866c5ca15d381f7fee
References: #3653

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/sqlalchemy/ext/hybrid.py b/lib/sqlalchemy/ext/hybrid.py
index 18516eae3..2f473fd31 100644
--- a/lib/sqlalchemy/ext/hybrid.py
+++ b/lib/sqlalchemy/ext/hybrid.py
@@ -771,7 +771,7 @@ class hybrid_property(interfaces.InspectionAttrInfo):
         producing method."""
 
         def _expr(cls):
-            return ExprComparator(expr(cls))
+            return ExprComparator(expr(cls), self)
         util.update_wrapper(_expr, expr)
 
         self.expr = _expr
@@ -819,10 +819,21 @@ class Comparator(interfaces.PropComparator):
 
 
 class ExprComparator(Comparator):
+    def __init__(self, expression, hybrid):
+        self.expression = expression
+        self.hybrid = hybrid
 
     def __getattr__(self, key):
         return getattr(self.expression, key)
 
+    @property
+    def info(self):
+        return self.hybrid.info
+
+    @property
+    def property(self):
+        return self.expression.property
+
     def operate(self, op, *other, **kwargs):
         return op(self.expression, *other, **kwargs)