[FIX] orm._auto_init: fallback to copy method when altering in-place varchar columns failed.

When a varchar column has a dependence on a view, we cannot change the size in-place,
we need to manually re-create the column with the correct type.

bzr revid: chs@openerp.com-20140217182045-qor70r3gb0fch2ki

openerp/osv/orm.py

@@ -2716,7 +2716,16 @@ class BaseModel(object):
                                 ('float8', 'float', get_pg_type(f)[1], '::'+get_pg_type(f)[1]),
                             ]
                             if f_pg_type == 'varchar' and f._type == 'char' and ((f.size is None and f_pg_size) or f_pg_size < f.size):
-                                cr.execute('ALTER TABLE "%s" ALTER COLUMN "%s" TYPE %s' % (self._table, k, pg_varchar(f.size)))
+                                try:
+                                    with cr.savepoint():
+                                        cr.execute('ALTER TABLE "%s" ALTER COLUMN "%s" TYPE %s' % (self._table, k, pg_varchar(f.size)))
+                                except psycopg2.NotSupportedError:
+                                    # In place alter table cannot be done because a view is depending of this field.
+                                    # Do a manual copy. This will drop the view (that will be recreated later)
+                                    cr.execute('ALTER TABLE "%s" RENAME COLUMN "%s" TO temp_change_size' % (self._table, k))
+                                    cr.execute('ALTER TABLE "%s" ADD COLUMN "%s" %s' % (self._table, k, pg_varchar(f.size)))
+                                    cr.execute('UPDATE "%s" SET "%s"=temp_change_size::%s' % (self._table, k, pg_varchar(f.size)))
+                                    cr.execute('ALTER TABLE "%s" DROP COLUMN temp_change_size CASCADE' % (self._table,))
                                 cr.commit()
                                 _schema.debug("Table '%s': column '%s' (type varchar) changed size from %s to %s",
                                     self._table, k, f_pg_size or 'unlimited', f.size or 'unlimited')

openerp/sql_db.py

@@ -3,7 +3,7 @@
 #
 #    OpenERP, Open Source Management Solution
 #    Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>).
-#    Copyright (C) 2010-2013 OpenERP s.a. (<http://openerp.com>).
+#    Copyright (C) 2010-2014 OpenERP s.a. (<http://openerp.com>).
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU Affero General Public License as
@@ -27,8 +27,10 @@ the database, *not* a database abstraction toolkit. Database abstraction is what
 the ORM does, in fact.
 """
 
+from contextlib import contextmanager
 from functools import wraps
 import logging
+import time
 import psycopg2.extensions
 from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT, ISOLATION_LEVEL_READ_COMMITTED, ISOLATION_LEVEL_REPEATABLE_READ
 from psycopg2.pool import PoolError
@@ -344,6 +346,19 @@ class Cursor(object):
         """
         return self._cnx.rollback()
 
+    @contextmanager
+    @check
+    def savepoint(self):
+        """context manager entering in a new savepoint"""
+        name = hex(int(time.time() * 1000))[1:]
+        self.execute("SAVEPOINT %s" % (name,))
+        try:
+            yield
+            self.execute('RELEASE SAVEPOINT %s' % (name,))
+        except Exception:
+            self.execute('ROLLBACK TO SAVEPOINT %s' % (name,))
+            raise
+
     @check
     def __getattr__(self, name):
         return getattr(self._obj, name)