fix: eliminate stale FTS results after consolidation

crates/icm-store/src/schema.rs

@@ -1,6 +1,6 @@
 use rusqlite::Connection;
 
-use icm_core::IcmError;
+use icm_core::{IcmError, IcmResult};
 
 use crate::store::db_err;
 
@@ -131,7 +131,7 @@ pub fn init_db_with_dims(conn: &Connection, embedding_dims: usize) -> Result<(),
                 VALUES('delete', old.rowid, old.id, old.topic, old.summary, old.keywords);
             END;
 
-            CREATE TRIGGER memories_au AFTER UPDATE ON memories BEGIN
+            CREATE TRIGGER memories_au AFTER UPDATE OF topic, summary, keywords ON memories BEGIN
                 INSERT INTO memories_fts(memories_fts, rowid, id, topic, summary, keywords)
                 VALUES('delete', old.rowid, old.id, old.topic, old.summary, old.keywords);
                 INSERT INTO memories_fts(rowid, id, topic, summary, keywords)
@@ -259,6 +259,11 @@ pub fn init_db_with_dims(conn: &Connection, embedding_dims: usize) -> Result<(),
             .map_err(db_err)?;
     }
 
+    // Migration: scope FTS UPDATE trigger to indexed columns only (fixes #44).
+    // The old trigger fired on ANY update (including update_access, apply_decay)
+    // which churned the FTS index and could create ghost entries.
+    migrate_fts_update_trigger(conn)?;
+
     // sqlite-vec virtual table for vector search (dimension-aware)
     let vec_exists: bool = conn
         .query_row(
@@ -293,6 +298,46 @@ pub fn init_db_with_dims(conn: &Connection, embedding_dims: usize) -> Result<(),
     Ok(())
 }
 
+/// Migrate existing DBs: replace the broad `memories_au` trigger with one
+/// scoped to `UPDATE OF topic, summary, keywords` so that `update_access` /
+/// `apply_decay` no longer churn the FTS index.  Also rebuilds the FTS index
+/// to purge any ghost entries accumulated before this fix.
+fn migrate_fts_update_trigger(conn: &Connection) -> IcmResult<()> {
+    // Check if the trigger already has the scoped form by inspecting its SQL.
+    let trigger_sql: Option<String> = conn
+        .query_row(
+            "SELECT sql FROM sqlite_master WHERE type='trigger' AND name='memories_au'",
+            [],
+            |row| row.get(0),
+        )
+        .ok();
+
+    let needs_migration = match &trigger_sql {
+        // Trigger exists but uses the old broad form (no OF clause).
+        Some(sql) => !sql.contains("UPDATE OF"),
+        // Trigger doesn't exist — FTS table was just created with the new form.
+        None => false,
+    };
+
+    if needs_migration {
+        conn.execute_batch(
+            "
+            DROP TRIGGER IF EXISTS memories_au;
+            CREATE TRIGGER memories_au AFTER UPDATE OF topic, summary, keywords ON memories BEGIN
+                INSERT INTO memories_fts(memories_fts, rowid, id, topic, summary, keywords)
+                VALUES('delete', old.rowid, old.id, old.topic, old.summary, old.keywords);
+                INSERT INTO memories_fts(rowid, id, topic, summary, keywords)
+                VALUES (new.rowid, new.id, new.topic, new.summary, new.keywords);
+            END;
+            INSERT INTO memories_fts(memories_fts) VALUES('rebuild');
+            ",
+        )
+        .map_err(db_err)?;
+    }
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/icm-store/src/store.rs

@@ -733,6 +733,17 @@ impl MemoryStore for SqliteStore {
             return Err(e);
         }
 
+        // Rebuild FTS index to eliminate any ghost entries from the external
+        // content table.  This guarantees search results stay consistent after
+        // bulk deletes (fixes #44).
+        if let Err(e) = self
+            .conn
+            .execute_batch("INSERT INTO memories_fts(memories_fts) VALUES('rebuild');")
+        {
+            let _ = self.conn.execute_batch("ROLLBACK;");
+            return Err(IcmError::Database(e.to_string()));
+        }
+
         self.conn.execute_batch("COMMIT;").map_err(db_err)?;
         Ok(())
     }
@@ -2157,6 +2168,65 @@ mod tests {
         assert_eq!(store.get_by_topic("topic-b").unwrap().len(), 1);
     }
 
+    /// Reproduces issue #44: after consolidation, recall should only return the
+    /// consolidated memory — not stale fragments from the originals.
+    #[test]
+    fn test_consolidate_no_stale_fts_results() {
+        let store = test_store();
+
+        // Step 1: store 3 related memories on the same topic
+        store
+            .store(make_memory(
+                "errors-resolved",
+                "fix: null pointer in parser",
+            ))
+            .unwrap();
+        store
+            .store(make_memory(
+                "errors-resolved",
+                "fix: timeout in HTTP client",
+            ))
+            .unwrap();
+        store
+            .store(make_memory(
+                "errors-resolved",
+                "fix: race condition in cache",
+            ))
+            .unwrap();
+
+        // Verify FTS finds them before consolidation
+        let before = store.search_fts("fix", 10).unwrap();
+        assert_eq!(before.len(), 3);
+
+        // Step 2: consolidate
+        let consolidated = make_memory(
+            "errors-resolved",
+            "All errors resolved: parser, HTTP, cache",
+        );
+        store
+            .consolidate_topic("errors-resolved", consolidated)
+            .unwrap();
+
+        // Step 3: recall — should only return the consolidated memory
+        let after = store.search_fts("fix", 10).unwrap();
+        assert!(
+            after.len() <= 1,
+            "expected at most 1 result after consolidation, got {}",
+            after.len()
+        );
+
+        // The consolidated memory should be findable
+        let consolidated_results = store.search_fts("errors resolved parser", 10).unwrap();
+        assert_eq!(consolidated_results.len(), 1);
+        assert!(consolidated_results[0]
+            .summary
+            .contains("All errors resolved"));
+
+        // Verify topic has exactly 1 memory
+        let topic_mems = store.get_by_topic("errors-resolved").unwrap();
+        assert_eq!(topic_mems.len(), 1);
+    }
+
     // === MemoirStore tests ===
 
     #[test]