[FIX] mail: guest search error

Before this PR, I guest searching in discuss would get an access error.
This is because the search is searching in the attachments that the guest can't
access.

task-3637314

closes odoo/odoo#146110

Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/models/mail_message.py

@@ -954,7 +954,8 @@ class Message(models.Model):
             # we replace every space by a % to avoid hard spacing matching
             search_term = search_term.replace(" ", "%")
             domain = expression.AND([domain, expression.OR([
-                [("attachment_ids.name", "ilike", search_term)],
+                # sudo: access to attachment is allowed if you have access to the parent model
+                [("attachment_ids", "in", self.env["ir.attachment"].sudo()._search([("name", "ilike", search_term)]))],
                 [("body", "ilike", search_term)],
                 [("subject", "ilike", search_term)],
                 [("subtype_id.description", "ilike", search_term)],

addons/mail/static/tests/tours/discuss_channel_public_tour.js

@@ -130,5 +130,24 @@ registry.category("web_tour.tours").add("discuss_channel_public_tour.js", {
                 await contains(".o-mail-AttachmentCard", { text: "extra.txt", count: 0 });
             },
         },
+        {
+            content: "Open search panel",
+            trigger: "button[title='Search Messages']",
+        },
+        {
+            content: "Search for the attachment name",
+            trigger: ".o_searchview_input",
+            run: "text text.txt",
+        },
+        {
+            content: "Trigger the search",
+            trigger: "button[aria-label='Search button']",
+        },
+        {
+            content: "Check that searched message contains the attachment",
+            trigger:
+                '.o-mail-SearchMessagesPanel .o-mail-Message .o-mail-AttachmentCard:contains("text.txt")',
+            run() {},
+        },
     ],
 });