[IMP] util/models: check m2m tables on model rename

When renaming a model we need to check m2m tables that may need to be
renamed as well. Otherwise the ORM will create a new table that would be
empty. If the data is handled directly in the scripts the ignore
parameter can be used to avoid warnings.

Author: aj-fuentes

src/util/models.py

@@ -24,10 +24,12 @@
     explode_execute,
     explode_query_range,
     format_query,
+    get_columns,
     get_m2m_tables,
     get_value_or_en_translation,
     parallel_execute,
     table_exists,
+    target_of,
     view_exists,
 )
 
@@ -268,7 +270,7 @@ def _replace_model_in_computed_custom_fields(cr, source, target):
         )
 
 
-def rename_model(cr, old, new, rename_table=True):
+def rename_model(cr, old, new, rename_table=True, ignore_m2m=()):
     """
     Rename a model.
 
@@ -285,6 +287,70 @@ def rename_model(cr, old, new, rename_table=True):
         new_table = table_of_model(cr, new)
         if new_table != old_table:
             pg_rename_table(cr, old_table, new_table)
+            m2m_tables = [t for t in get_m2m_tables(cr, new_table) if t not in ignore_m2m]
+            cr.execute(
+                """
+                SELECT relation_table,
+                       ARRAY_AGG(id)
+                  FROM ir_model_fields
+                 WHERE ttype = 'many2many'
+                   AND relation_table = ANY(%s)
+                   AND (  model = %s
+                       OR relation = %s)
+              GROUP BY relation_table
+              ORDER BY relation_table
+                """,
+                [m2m_tables, old, old],
+            )
+            for m2m_table, field_ids in cr.fetchall():
+                if not table_exists(cr, m2m_table):
+                    # Possibly handled in the upgrade scripts already
+                    continue
+                new_m2m_table = m2m_table
+                m = re.match(r"(\w+)_{}_rel".format(old_table), m2m_table) or re.match(
+                    r"{}_(\w+)_rel".format(old_table), m2m_table
+                )
+                if m:
+                    new_m2m_table = "{}_{}_rel".format(*sorted([m.group(1), new_table]))
+                    # For long table names the FK constraint is dropped when renaming the table
+                    # We need the constraint to correctly identify the FK targets
+                    # They will be dropped and recreated anyway here below
+                    pg_rename_table(cr, m2m_table, new_m2m_table, remove_constraints=False)
+                    _logger.info("Renamed m2m table %s to %s", m2m_table, new_m2m_table)
+                    cr.execute(
+                        "UPDATE ir_model_fields SET relation_table = %s WHERE id IN %s",
+                        [new_m2m_table, tuple(field_ids)],
+                    )
+                for m2m_col in get_columns(cr, new_m2m_table).iter_unquoted():
+                    col_info = target_of(cr, new_m2m_table, m2m_col)
+                    if col_info and col_info[0] == new_table and col_info[1] == "id":
+                        old_col, new_col = map("{}_id".format, [old_table, new_table])
+                        if m2m_col == old_col:
+                            query = format_query(
+                                cr,
+                                """
+                                ALTER TABLE {m2m_table}
+                              RENAME COLUMN {old_col} TO {new_col};
+
+                                ALTER TABLE {m2m_table}
+                            DROP CONSTRAINT {old_constraint_name},
+                            ADD FOREIGN KEY ({new_col}) REFERENCES {new_table} (id)
+                                """,
+                                m2m_table=new_m2m_table,
+                                old_col=old_col,
+                                new_col=new_col,
+                                old_constraint_name=col_info[2],
+                                new_table=new_table,
+                            )
+                            cr.execute(query)
+                            _logger.info("Renamed m2m column of table %s from %s to %s", m2m_table, old_col, new_col)
+                        else:
+                            _logger.warning(
+                                "Possibly missing rename: the column %s of m2m table %s references the table %s",
+                                m2m_col,
+                                m2m_table,
+                                new_table,
+                            )
 
     updates = [("wkf", "osv")] if table_exists(cr, "wkf") else []
     updates += [(ir.table, ir.res_model) for ir in indirect_references(cr) if ir.res_model]