[IMP] util.merge_module

Explicit exception when `into` module does not exists, instead of an
obscure KeyError.

Part-of: #315
Signed-off-by: Christophe Simonis (chs) <[email protected]>

Author: KangOl

src/util/modules.py

@@ -395,10 +395,12 @@ def merge_module(cr, old, into, update_dependers=True):
     if old not in mod_ids:
         # this can happen in case of temp modules added after a release if the database does not
         # know about this module, i.e: account_full_reconcile in 9.0
-        # `into` should be know. Let it crash if not
         _logger.log(NEARLYWARN, "Unknown module %s. Skip merge into %s.", old, into)
         return
 
+    if into not in mod_ids:
+        raise UnknownModuleError(into)
+
     def _up(table, old, new):
         cr.execute(
             """