From cd99c12f05b10cb1b3a07b7b4fcd9fb89785f7a8 Mon Sep 17 00:00:00 2001
From: Justin Bronn <jbronn@gmail.com>
Date: Fri, 5 Oct 2012 18:41:50 -0700
Subject: [PATCH] Fixed `F()` expression regressions in GeoDjango caused by
 recent datastructure changes in `SQLEvaluator`.

---
 django/contrib/gis/db/backends/base.py                 | 10 ++++++++++
 django/contrib/gis/db/backends/mysql/operations.py     |  2 +-
 django/contrib/gis/db/backends/oracle/operations.py    |  2 +-
 django/contrib/gis/db/backends/postgis/operations.py   |  2 +-
 .../contrib/gis/db/backends/spatialite/operations.py   |  2 +-
 5 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/django/contrib/gis/db/backends/base.py b/django/contrib/gis/db/backends/base.py
index 2b8924d92e..0bd598997c 100644
--- a/django/contrib/gis/db/backends/base.py
+++ b/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.')
diff --git a/django/contrib/gis/db/backends/mysql/operations.py b/django/contrib/gis/db/backends/mysql/operations.py
index 7152f4682d..0c1be624f1 100644
--- a/django/contrib/gis/db/backends/mysql/operations.py
+++ b/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
diff --git a/django/contrib/gis/db/backends/oracle/operations.py b/django/contrib/gis/db/backends/oracle/operations.py
index 392feb129b..35a4d9491d 100644
--- a/django/contrib/gis/db/backends/oracle/operations.py
+++ b/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)
diff --git a/django/contrib/gis/db/backends/postgis/operations.py b/django/contrib/gis/db/backends/postgis/operations.py
index 18a59d1240..ff9110de01 100644
--- a/django/contrib/gis/db/backends/postgis/operations.py
+++ b/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
 
diff --git a/django/contrib/gis/db/backends/spatialite/operations.py b/django/contrib/gis/db/backends/spatialite/operations.py
index 80f05ef076..5f76501ef1 100644
--- a/django/contrib/gis/db/backends/spatialite/operations.py
+++ b/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.