Fixed `F()` expression regressions in GeoDjango caused by recent datastructure changes in `SQLEvaluator`.

django/contrib/gis/db/backends/base.py

@@ -116,6 +116,16 @@ class BaseSpatialOperations(object):
         """
         raise NotImplementedError
 
+    def get_expression_column(self, evaluator):
+        """
+        Helper method to return the quoted column string from the evaluator
+        for its expression.
+        """
+        for expr, col_tup in evaluator.cols:
+            if expr is evaluator.expression:
+                return '%s.%s' % tuple(map(self.quote_name, col_tup))
+        raise Exception("Could not find the column for the expression.")
+
     # Spatial SQL Construction
     def spatial_aggregate_sql(self, agg):
         raise NotImplementedError('Aggregate support not implemented for this spatial backend.')

django/contrib/gis/db/backends/mysql/operations.py

@@ -44,7 +44,7 @@ class MySQLOperations(DatabaseOperations, BaseSpatialOperations):
         modify the placeholder based on the contents of the given value.
         """
         if hasattr(value, 'expression'):
-            placeholder = '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))
+            placeholder = placeholder % self.get_expression_column(value)
         else:
             placeholder = '%s(%%s)' % self.from_text
         return placeholder

django/contrib/gis/db/backends/oracle/operations.py

@@ -213,7 +213,7 @@ class OracleOperations(DatabaseOperations, BaseSpatialOperations):
                 placeholder = '%s'
             # No geometry value used for F expression, substitue in
             # the column name instead.
-            return placeholder % '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))
+            return placeholder % self.get_expression_column(value)
         else:
             if transform_value(value, f.srid):
                 return '%s(SDO_GEOMETRY(%%s, %s), %s)' % (self.transform, value.srid, f.srid)

django/contrib/gis/db/backends/postgis/operations.py

@@ -381,7 +381,7 @@ class PostGISOperations(DatabaseOperations, BaseSpatialOperations):
             # If this is an F expression, then we don't really want
             # a placeholder and instead substitute in the column
             # of the expression.
-            placeholder = placeholder % '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))
+            placeholder = placeholder % self.get_expression_column(value)
 
         return placeholder
 

django/contrib/gis/db/backends/spatialite/operations.py

@@ -208,7 +208,7 @@ class SpatiaLiteOperations(DatabaseOperations, BaseSpatialOperations):
                 placeholder = '%s'
             # No geometry value used for F expression, substitue in
             # the column name instead.
-            return placeholder % '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))
+            return placeholder % self.get_expression_column(value)
         else:
             if transform_value(value, f.srid):
                 # Adding Transform() to the SQL placeholder.