Merge pull request 'Prevent duplicated posts in 'all' timeline' (#917) from dup-timeline into main

Reviewed-on: https://git.joinplu.me/Plume/Plume/pulls/917

CHANGELOG.md

@@ -28,6 +28,7 @@
 - Upsert posts and media instead of trying to insert and fail (#912)
 - Update post's ActivityPub id when published by update (#915)
 - Calculate media URI properly even when MEDIA_UPLOAD_DIRECTORY configured (#916)
+- Prevent duplicated posts in 'all' timeline (#917)
 
 ## [[0.6.0]] - 2020-12-29
 

plume-models/src/timeline/mod.rs

@@ -223,6 +223,9 @@ impl Timeline {
     }
 
     pub fn add_post(&self, conn: &Connection, post: &Post) -> Result<()> {
+        if self.includes_post(conn, post)? {
+            return Ok(());
+        }
         diesel::insert_into(timeline::table)
             .values(TimelineEntry {
                 post_id: post.id,
@@ -236,6 +239,16 @@ impl Timeline {
         let query = TimelineQuery::parse(&self.query)?;
         query.matches(conn, self, post, kind)
     }
+
+    fn includes_post(&self, conn: &Connection, post: &Post) -> Result<bool> {
+        diesel::dsl::select(diesel::dsl::exists(
+            timeline::table
+                .filter(timeline::timeline_id.eq(self.id))
+                .filter(timeline::post_id.eq(post.id)),
+        ))
+        .get_result(conn)
+        .map_err(Error::from)
+    }
 }
 
 #[cfg(test)]