Ticket #13574: django_m2m_field_name.diff

django/db/models/sql/query.py

@@ -1240 +1240 @@
                                 to_col2, opts, target) = cached_data
                     else:
                         table1 = field.m2m_db_table()
-                        from_col1 = opts.pk.column
+                        from_col1 = field.m2m_to_field_name()
                         to_col1 = field.m2m_column_name()
                         opts = field.rel.to._meta
                         table2 = opts.db_table
                         from_col2 = field.m2m_reverse_name()
-                        to_col2 = opts.pk.column
+                        to_col2 = field.m2m_reverse_to_field_name()
                         target = opts.pk
                         orig_opts._join_cache[name] = (table1, from_col1,
                                 to_col1, table2, from_col2, to_col2, opts,
@@ -1293 +1293 @@
                                 to_col2, opts, target) = cached_data
                     else:
                         table1 = field.m2m_db_table()
-                        from_col1 = opts.pk.column
+                        from_col1 = field.m2m_reverse_to_field_name()
                         to_col1 = field.m2m_reverse_name()
                         opts = orig_field.opts
                         table2 = opts.db_table
                         from_col2 = field.m2m_column_name()
-                        to_col2 = opts.pk.column
+                        to_col2 = field.m2m_to_field_name()
                         target = opts.pk
                         orig_opts._join_cache[name] = (table1, from_col1,
                                 to_col1, table2, from_col2, to_col2, opts,

django/db/models/fields/related.py

@@ -1020 +1020 @@
             return getattr(self, cache_attr)
         for f in self.rel.through._meta.fields:
             if hasattr(f,'rel') and f.rel and f.rel.to == related.model:
-                setattr(self, cache_attr, getattr(f, attr))
+                if attr == 'to_field':
+                    setattr(self, cache_attr, f.rel.field_name)
+                else:
+                    setattr(self, cache_attr, getattr(f, attr))
                 return getattr(self, cache_attr)
 
     def _get_m2m_reverse_attr(self, related, attr):
@@ -1042 +1045 @@
                     else:
                         found = True
                 else:
-                    setattr(self, cache_attr, getattr(f, attr))
+                    if attr == 'to_field':
+                        setattr(self, cache_attr, f.rel.field_name)
+                    else:
+                        setattr(self, cache_attr, getattr(f, attr))
                     break
         return getattr(self, cache_attr)
 
@@ -1129 +1135 @@
         self.m2m_field_name = curry(self._get_m2m_attr, related, 'name')
         self.m2m_reverse_field_name = curry(self._get_m2m_reverse_attr, related, 'name')
 
+        self.m2m_to_field_name = curry(self._get_m2m_attr, related, 'to_field')
+        self.m2m_reverse_to_field_name = curry(self._get_m2m_reverse_attr, related, 'to_field')
+
     def set_attributes_from_rel(self):
         pass