- merged #1401 branch from bitbucket

- resolved some serious speed hits I missed, we need to ensure
only deannotated columns are used in the local/remote collections and soforth
so that hash lookups against mapped columns don't dig into __eq__()
- fix some other parity mismatches regarding stuff from [ticket:2453],
including finding another case where _deep_annotate() was doing the wrong thing,
new tests.
- [feature] Major rewrite of relationship()
internals now allow join conditions which
include columns pointing to themselves
within composite foreign keys.   A new
API for very specialized primaryjoin conditions
is added, allowing conditions based on
SQL functions, CAST, etc. to be handled
by placing the annotation functions
remote() and foreign() inline within the
expression when necessary.  Previous recipes
using the semi-private _local_remote_pairs
approach can be upgraded to this new
approach. [ticket:1401]

1 files changed, 28 insertions, 7 deletions

diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index f9a3863da..d8ad7c3fa 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -1584,18 +1584,35 @@ class ClauseElement(Visitable):
             return id(self)
 
     def _annotate(self, values):
-        """return a copy of this ClauseElement with the given annotations
-        dictionary.
+        """return a copy of this ClauseElement with annotations
+        updated by the given dictionary.
 
         """
         return sqlutil.Annotated(self, values)
 
-    def _deannotate(self):
-        """return a copy of this ClauseElement with an empty annotations
-        dictionary.
+    def _with_annotations(self, values):
+        """return a copy of this ClauseElement with annotations
+        replaced by the given dictionary.
 
         """
-        return self._clone()
+        return sqlutil.Annotated(self, values)
+
+    def _deannotate(self, values=None, clone=False):
+        """return a copy of this :class:`.ClauseElement` with annotations
+        removed.
+        
+        :param values: optional tuple of individual values
+         to remove.
+
+        """
+        if clone:
+            # clone is used when we are also copying
+            # the expression for a deep deannotation
+            return self._clone()
+        else:
+            # if no clone, since we have no annotations we return
+            # self
+            return self
 
     def unique_params(self, *optionaldict, **kwargs):
         """Return a copy with :func:`bindparam()` elements replaced.
@@ -2195,7 +2212,7 @@ class ColumnElement(ClauseElement, _CompareMixin):
         for oth in to_compare:
             if use_proxies and self.shares_lineage(oth):
                 return True
-            elif oth is self:
+            elif hash(oth) == hash(self):
                 return True
         else:
             return False
@@ -3403,6 +3420,10 @@ class _BinaryExpression(ColumnElement):
             raise TypeError("Boolean value of this clause is not defined")
 
     @property
+    def is_comparison(self):
+        return operators.is_comparison(self.operator)
+
+    @property
     def _from_objects(self):
         return self.left._from_objects + self.right._from_objects