Improved error message when attempting to fetch non-local object (fixes

#2715) (#2717)

crates/apub/src/http/comment.rs

@@ -1,10 +1,9 @@
 use crate::{
-  http::{create_apub_response, create_apub_tombstone_response},
+  http::{create_apub_response, create_apub_tombstone_response, err_object_not_local},
   objects::comment::ApubComment,
 };
 use activitypub_federation::traits::ApubObject;
 use actix_web::{web, web::Path, HttpResponse};
-use diesel::result::Error::NotFound;
 use lemmy_api_common::context::LemmyContext;
 use lemmy_db_schema::{newtypes::CommentId, source::comment::Comment, traits::Crud};
 use lemmy_utils::error::LemmyError;
@@ -24,7 +23,7 @@ pub(crate) async fn get_apub_comment(
   let id = CommentId(info.comment_id.parse::<i32>()?);
   let comment: ApubComment = Comment::read(context.pool(), id).await?.into();
   if !comment.local {
-    return Err(NotFound.into());
+    return Err(err_object_not_local());
   }
 
   if !comment.deleted && !comment.removed {

crates/apub/src/http/mod.rs

@@ -100,6 +100,10 @@ fn create_apub_tombstone_response<T: Into<Url>>(id: T) -> HttpResponse {
     .json(WithContext::new(tombstone, CONTEXT.deref().clone()))
 }
 
+fn err_object_not_local() -> LemmyError {
+  LemmyError::from_message("Object not local, fetch it from original instance")
+}
+
 #[derive(Deserialize)]
 pub struct ActivityQuery {
   type_: String,
@@ -123,8 +127,10 @@ pub(crate) async fn get_activity(
   let activity = Activity::read_from_apub_id(context.pool(), &activity_id).await?;
 
   let sensitive = activity.sensitive.unwrap_or(true);
-  if !activity.local || sensitive {
-    Ok(HttpResponse::NotFound().finish())
+  if !activity.local {
+    return Err(err_object_not_local());
+  } else if sensitive {
+    Ok(HttpResponse::Forbidden().finish())
   } else {
     Ok(create_json_apub_response(activity.data))
   }

crates/apub/src/http/post.rs

@@ -1,10 +1,9 @@
 use crate::{
-  http::{create_apub_response, create_apub_tombstone_response},
+  http::{create_apub_response, create_apub_tombstone_response, err_object_not_local},
   objects::post::ApubPost,
 };
 use activitypub_federation::traits::ApubObject;
 use actix_web::{web, HttpResponse};
-use diesel::result::Error::NotFound;
 use lemmy_api_common::context::LemmyContext;
 use lemmy_db_schema::{newtypes::PostId, source::post::Post, traits::Crud};
 use lemmy_utils::error::LemmyError;
@@ -24,7 +23,7 @@ pub(crate) async fn get_apub_post(
   let id = PostId(info.post_id.parse::<i32>()?);
   let post: ApubPost = Post::read(context.pool(), id).await?.into();
   if !post.local {
-    return Err(NotFound.into());
+    return Err(err_object_not_local());
   }
 
   if !post.deleted && !post.removed {