memoize current options and joins w with_entities/with_only_cols

Fixed further regressions in the same area as that of :ticket:`6052` where
loader options as well as invocations of methods like
:meth:`_orm.Query.join` would fail if the left side of the statement for
which the option/join depends upon were replaced by using the
:meth:`_orm.Query.with_entities` method, or when using 2.0 style queries
when using the :meth:`_sql.Select.with_only_columns` method. A new set of
state has been added to the objects which tracks the "left" entities that
the options / join were made against which is memoized when the lead
entities are changed.

Fixes: #6503
Fixes: #6253
Change-Id: I211b2af98b0b20d1263fb15dc513884dcc5de6a4

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index c9a601f99..28b4bfb2d 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -750,6 +750,18 @@ class LoaderOption(ORMOption):
 
     _is_compile_state = True
 
+    def process_compile_state_replaced_entities(
+        self, compile_state, mapper_entities
+    ):
+        """Apply a modification to a given :class:`.CompileState`,
+        given entities that were replaced by with_only_columns() or
+        with_entities().
+
+        .. versionadded:: 1.4.19
+
+        """
+        self.process_compile_state(compile_state)
+
     def process_compile_state(self, compile_state):
         """Apply a modification to a given :class:`.CompileState`."""