[FIX] core: disable werkzeug's merge_slashes

Werkzeug 1.0 adds a `merge_slashes` feature which calls rule.build()
*during match*[0] (= during dispatch).

However at this point our environment still contains an invalid /
placeholder UID, so `display_name` / `name_get()` fails dramatically.

One possibility would be to update the slugifying to not access the
record (outside of the id) if the environment is not "proper", an
other alternative is to just disable the feature since it seems to not
have been necessary so far.

The latter seems less hacky so do that for now, we can always swap the
solution later if we need to.

[0] https://github.com/pallets/werkzeug/blame/048cdfd9b969c0c3a133d7ff43b8ad1ad6a673ec/src/werkzeug/routing.py#L904

odoo/addons/base/models/ir_http.py

@@ -269,7 +269,9 @@ class IrHttp(models.AbstractModel):
             for url, endpoint, routing in cls._generate_routing_rules(mods, converters=cls._get_converters()):
                 xtra_keys = 'defaults subdomain build_only strict_slashes redirect_to alias host'.split()
                 kw = {k: routing[k] for k in xtra_keys if k in routing}
-                routing_map.add(werkzeug.routing.Rule(url, endpoint=endpoint, methods=routing['methods'], **kw))
+                rule = werkzeug.routing.Rule(url, endpoint=endpoint, methods=routing['methods'], **kw)
+                rule.merge_slashes = False
+                routing_map.add(rule)
             cls._routing_map[key] = routing_map
         return cls._routing_map[key]
 

odoo/http.py

@@ -1268,7 +1268,9 @@ class Root(object):
         _logger.info("Generating nondb routing")
         routing_map = werkzeug.routing.Map(strict_slashes=False, converters=None)
         for url, endpoint, routing in odoo.http._generate_routing_rules([''] + odoo.conf.server_wide_modules, True):
-            routing_map.add(werkzeug.routing.Rule(url, endpoint=endpoint, methods=routing['methods']))
+            rule = werkzeug.routing.Rule(url, endpoint=endpoint, methods=routing['methods'])
+            rule.merge_slashes = False
+            routing_map.add(rule)
         return routing_map
 
     def __call__(self, environ, start_response):