Merge pull request #5551 from meilisearch/dont-intern-without-typo

Only intern in case of single-typo when looking for single typoes

crates/meilisearch/tests/search/mod.rs

@@ -112,6 +112,26 @@ async fn simple_search() {
         .await;
 }
 
+/// See <https://github.com/meilisearch/meilisearch/issues/5547>
+#[actix_rt::test]
+async fn bug_5547() {
+    let server = Server::new().await;
+    let index = server.index("big_fst");
+    let (response, _code) = index.create(None).await;
+    index.wait_task(response.uid()).await.succeeded();
+
+    let mut documents = Vec::new();
+    for i in 0..65_535 {
+        documents.push(json!({"id": i, "title": format!("title{i}")}));
+    }
+
+    let (response, _code) = index.add_documents(json!(documents), Some("id")).await;
+    index.wait_task(response.uid()).await.succeeded();
+    let (response, code) = index.search_post(json!({"q": "title"})).await;
+    assert_eq!(code, 200);
+    snapshot!(response["hits"], @r###"[{"id":0,"title":"title0"},{"id":1,"title":"title1"},{"id":10,"title":"title10"},{"id":100,"title":"title100"},{"id":101,"title":"title101"},{"id":102,"title":"title102"},{"id":103,"title":"title103"},{"id":104,"title":"title104"},{"id":105,"title":"title105"},{"id":106,"title":"title106"},{"id":107,"title":"title107"},{"id":108,"title":"title108"},{"id":1000,"title":"title1000"},{"id":1001,"title":"title1001"},{"id":1002,"title":"title1002"},{"id":1003,"title":"title1003"},{"id":1004,"title":"title1004"},{"id":1005,"title":"title1005"},{"id":1006,"title":"title1006"},{"id":1007,"title":"title1007"}]"###);
+}
+
 #[actix_rt::test]
 async fn search_with_stop_word() {
     // related to https://github.com/meilisearch/meilisearch/issues/4984

crates/milli/src/search/new/query_term/compute_derivations.rs

@@ -92,12 +92,12 @@ fn find_one_typo_derivations(
     let mut stream = fst.search_with_state(Intersection(starts, &dfa)).into_stream();
 
     while let Some((derived_word, state)) = stream.next() {
-        let derived_word = std::str::from_utf8(derived_word)?;
-        let derived_word = ctx.word_interner.insert(derived_word.to_owned());
         let d = dfa.distance(state.1);
         match d.to_u8() {
             0 => (),
             1 => {
+                let derived_word = std::str::from_utf8(derived_word)?;
+                let derived_word = ctx.word_interner.insert(derived_word.to_owned());
                 let cf = visit(derived_word)?;
                 if cf.is_break() {
                     break;