[FIX] base: serve_fallback infinite redirection

Create an attachment with an URL to a static file that does not exists,
e.g. '/web/static/idontexist.png'. Inside your browser try to access
that file, open <localhost:8069/web/static/idontexist.png>. The browser
fails with a "Too Many Redirections" error.

When a path is not found, nor in the static files, nor in the
controllers, `_serve_fallback` kicks in and attempt to find a resource
outside of the router that matches the URL. In case it finds an
attachment with a matching URL, it'll deliver it.

In this specific case, it finds our attachment and return a redirection
to it's URL, which is the same URL as the request hence it loops back.

Don't deliver URL attachments via `_serve_fallback`, only deliver stored
files.

closes odoo/odoo#156323

X-original-commit: d2bea592db6a66d531b83437d42b273606f629f1
Signed-off-by: Julien Castiaux (juc) <juc@odoo.com>

odoo/addons/base/models/ir_http.py

@@ -240,7 +240,7 @@ class IrHttp(models.AbstractModel):
     def _serve_fallback(cls):
         model = request.env['ir.attachment']
         attach = model.sudo()._get_serve_attachment(request.httprequest.path)
-        if attach:
+        if attach and (attach.store_fname or attach.db_datas):
             return Stream.from_attachment(attach).get_response()
 
     @classmethod

odoo/addons/test_http/tests/test_static.py

@@ -6,6 +6,7 @@ from http import HTTPStatus
 from os.path import basename, join as opj
 from unittest.mock import patch
 from freezegun import freeze_time
+from urllib3.util import parse_url
 
 import odoo
 from odoo.tests import new_test_user, tagged, RecordCapturer
@@ -311,6 +312,22 @@ class TestHttpStatic(TestHttpStaticCommon):
         self.assertFalse(att.checksum)
         self.assertDownloadGizeh(f'/web/image/{att.id}')
 
+    def test_static19_fallback_redirection_loop(self):
+        bad_path = '/test_http/static/idontexist.png'
+        self.assertRaises(FileNotFoundError, file_open, bad_path[1:])
+
+        self.env['ir.attachment'].create({
+            'name': 'idontexist.png',
+            'mimetype': 'image/png',
+            'url': bad_path,
+            'public': True,
+        })
+
+        res = self.url_open(bad_path, allow_redirects=False)
+        location = parse_url(res.headers.get('Location', ''))
+        self.assertNotEqual(location.path, bad_path, "loop detected")
+        self.assertEqual(res.status_code, 404)
+
 
 @tagged('post_install', '-at_install')
 class TestHttpStaticLogo(TestHttpStaticCommon):