From cb283ac3161c64f0f11261b1a329a5158629a450 Mon Sep 17 00:00:00 2001
From: Greg Heartsfield <scsibug@imap.cc>
Date: Mon, 2 Jan 2023 17:18:11 -0600
Subject: [PATCH] fix: ensure that replaceable events are handled correctly
 regardless of order receieved

---
 src/db.rs     |  6 ++++--
 src/schema.rs | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/src/db.rs b/src/db.rs
index 0f55cc6..54e0211 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -415,9 +415,11 @@ pub fn write_event(conn: &mut PooledConnection, e: &Event) -> Result<usize> {
     // event with the same kind from the same author that was issued
     // earlier than this.
     if e.kind == 0 || e.kind == 3 || e.kind == 41 || (e.kind >= 10000 && e.kind < 20000) {
+	let author = hex::decode(&e.pubkey).ok();
+	// this is a backwards check - hide any events that were older.
         let update_count = tx.execute(
-            "UPDATE event SET hidden=TRUE WHERE id!=? AND kind=? AND author=? AND created_at <= ? and hidden!=TRUE",
-            params![ev_id, e.kind, hex::decode(&e.pubkey).ok(), e.created_at],
+            "UPDATE event SET hidden=TRUE WHERE hidden!=TRUE and kind=? and author=? and id NOT IN (SELECT id FROM event WHERE kind=? AND author=? ORDER BY created_at DESC LIMIT 1)",
+            params![e.kind, author, e.kind, author],
         )?;
         if update_count > 0 {
             info!(
diff --git a/src/schema.rs b/src/schema.rs
index d11b731..5c3b80d 100644
--- a/src/schema.rs
+++ b/src/schema.rs
@@ -20,7 +20,7 @@ pragma mmap_size = 17179869184; -- cap mmap at 16GB
 "##;
 
 /// Latest database version
-pub const DB_VERSION: usize = 11;
+pub const DB_VERSION: usize = 12;
 
 /// Schema definition
 const INIT_SQL: &str = formatcp!(
@@ -171,6 +171,9 @@ pub fn upgrade_db(conn: &mut PooledConnection) -> Result<()> {
             if curr_version == 10 {
                 curr_version = mig_10_to_11(conn)?;
             }
+            if curr_version == 11 {
+                curr_version = mig_11_to_12(conn)?;
+            }
 
             if curr_version == DB_VERSION {
                 info!(
@@ -468,3 +471,31 @@ PRAGMA user_version = 11;
     }
     Ok(11)
 }
+
+fn mig_11_to_12(conn: &mut PooledConnection) -> Result<usize> {
+    info!("database schema needs update from 11->12");
+    let start = Instant::now();
+    let tx = conn.transaction()?;
+    {
+        // Lookup every replaceable event
+        let mut stmt = tx.prepare("select kind,author from event where kind in (0,3,41) or (kind>=10000 and kind<20000) order by id;")?;
+        let mut replaceable_rows = stmt.query([])?;
+        while let Some(row) = replaceable_rows.next()? {
+            // we want to capture the event_id that had the tag, the tag name, and the tag hex value.
+            let event_kind: u64 = row.get(0)?;
+            let event_author: Vec<u8> = row.get(1)?;
+            tx.execute(
+                "UPDATE event SET hidden=TRUE WHERE hidden!=TRUE and kind=? and author=? and id NOT IN (SELECT id FROM event WHERE kind=? AND author=? ORDER BY created_at DESC LIMIT 1)",
+                params![event_kind, event_author, event_kind, event_author],
+            )?;
+        }
+        tx.execute("PRAGMA user_version = 12;", [])?;
+    }
+    tx.commit()?;
+    info!("database schema upgraded v11 -> v12 in {:?}", start.elapsed());
+    // vacuum after large table modification
+    let start = Instant::now();
+    conn.execute("VACUUM;", [])?;
+    info!("vacuumed DB after hidden event cleanup in {:?}", start.elapsed());
+    Ok(12)
+}