Fixed #24615 -- ordering by expression not part of SELECT

Fixed queries where an expression was used in order_by() but the
expression wasn't in the query's select clause (for example the
expression could be masked by .values() call)

Thanks to Trac alias MattBlack85 for the report.

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

@@ -12,5 +12,8 @@ class WKTAdapter(object):
             return False
         return self.wkt == other.wkt and self.srid == other.srid
 
+    def __hash__(self):
+        return hash((self.wkt, self.srid))
+
     def __str__(self):
         return self.wkt

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

@@ -28,6 +28,9 @@ class PostGISAdapter(object):
             return False
         return (self.ewkb == other.ewkb) and (self.srid == other.srid)
 
+    def __hash__(self):
+        return hash((self.ewkb, self.srid))
+
     def __str__(self):
         return self.getquoted()
 

django/db/models/sql/compiler.py

@@ -262,10 +262,17 @@ class SQLCompiler(object):
             descending = True if order == 'DESC' else False
 
             if col in self.query.annotation_select:
+                # Reference to expression in SELECT clause
                 order_by.append((
                     OrderBy(Ref(col, self.query.annotation_select[col]), descending=descending),
                     True))
                 continue
+            if col in self.query.annotations:
+                # References to an expression which is masked out of the SELECT clause
+                order_by.append((
+                    OrderBy(self.query.annotations[col], descending=descending),
+                    False))
+                continue
 
             if '.' in field:
                 # This came in through an extra(order_by=...) addition. Pass it