[FIX] web: sql constraint translation

The `check` decorator expects the context to be in the `kwargs`
or to be the last arguments of the method.

The `call_kw` route, which is decorated by the `check` decorator,
like every route,
expands its kwargs arguments.

Therefore, once in the `check` decorator,
the context is located in the `kwargs` key
of the kwargs.
(More simply, instead of
`kwargs.get('context', {})`
it's
`kwargs.get('kwargs', {}).get('context', {})`

As the context is not retrieved correctly,
the lang is not set correctly either,
and the sql constraints were not translated.

In 7.0, it worked, because there was a double
check, as the call_kw was called trough an rpc
(`dispatch_rpc`) call,
which was decorated by the `check` as well.

As a fix for 8.0, we apply the same logic,
we perform a double check, with an indirection.

The check decorator should probably be
refactored, but this cannot be done
in a stable release such as 8.0.

Closes #3634

addons/web/controllers/main.py

@@ -33,6 +33,7 @@ import openerp
 import openerp.modules.registry
 from openerp.addons.base.ir.ir_qweb import AssetsBundle, QWebTemplateNotFound
 from openerp.modules import get_module_resource
+from openerp.service import model as service_model
 from openerp.tools import topological_sort
 from openerp.tools.translate import _
 from openerp.tools import ustr
@@ -933,7 +934,10 @@ class DataSet(http.Controller):
         if method.startswith('_'):
             raise Exception("Access Denied: Underscore prefixed methods cannot be remotely called")
 
-        return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
+        @service_model.check
+        def checked_call(__dbname, *args, **kwargs):
+            return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
+        return checked_call(request.db, *args, **kwargs)
 
     @http.route('/web/dataset/call', type='json', auth="user")
     def call(self, model, method, args, domain_id=None, context_id=None):