Unify NO_VALUE and NEVER_SET

There's no real difference between these two constants
except they are used in different places and therefore allow
various codepaths to work largely by accident.   These
codepaths should be explicit.   Assign NO_VALUE and NEVER_SET
to the same constant and work towards having just one constant
for "we have no value to return right now".

Fixes: #4696
Change-Id: I7c324967952c1886bf202074d627323a2ad013cc

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index ccf05a783..3c26f7247 100644
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -2715,7 +2715,7 @@ class Mapper(InspectionAttr):
         return self._identity_key_from_state(state, attributes.PASSIVE_OFF)
 
     def _identity_key_from_state(
-        self, state, passive=attributes.PASSIVE_RETURN_NEVER_SET
+        self, state, passive=attributes.PASSIVE_RETURN_NO_VALUE
     ):
         dict_ = state.dict
         manager = state.manager
@@ -2769,7 +2769,7 @@ class Mapper(InspectionAttr):
         return {prop.key for prop in self._all_pk_props}
 
     def _get_state_attr_by_column(
-        self, state, dict_, column, passive=attributes.PASSIVE_RETURN_NEVER_SET
+        self, state, dict_, column, passive=attributes.PASSIVE_RETURN_NO_VALUE
     ):
         prop = self._columntoproperty[column]
         return state.manager[prop.key].impl.get(state, dict_, passive=passive)
@@ -2790,7 +2790,7 @@ class Mapper(InspectionAttr):
         )
 
     def _get_committed_state_attr_by_column(
-        self, state, dict_, column, passive=attributes.PASSIVE_RETURN_NEVER_SET
+        self, state, dict_, column, passive=attributes.PASSIVE_RETURN_NO_VALUE
     ):
 
         prop = self._columntoproperty[column]