From 40776ed4cd8e1a53e36354a39daf0805499e47bd Mon Sep 17 00:00:00 2001
From: ManyTheFish <many@meilisearch.com>
Date: Thu, 12 Jun 2025 11:05:08 +0200
Subject: [PATCH 1/2] add test reproducing #5650

---
 crates/meilisearch/tests/search/mod.rs | 73 ++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/crates/meilisearch/tests/search/mod.rs b/crates/meilisearch/tests/search/mod.rs
index ff6d3e2b8..b2d781e7f 100644
--- a/crates/meilisearch/tests/search/mod.rs
+++ b/crates/meilisearch/tests/search/mod.rs
@@ -2086,3 +2086,76 @@ async fn test_exact_typos_terms() {
     )
     .await;
 }
+
+#[actix_rt::test]
+async fn simple_search_changing_unrelated_settings() {
+    let server = Server::new_shared();
+    let index = server.unique_index();
+
+    let documents = DOCUMENTS.clone();
+    let (task, _status_code) = index.add_documents(documents, None).await;
+    index.wait_task(task.uid()).await.succeeded();
+
+    index
+        .search(json!({"q": "Dragon"}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(json_string!(response["hits"]), @r###"
+            [
+              {
+                "title": "How to Train Your Dragon: The Hidden World",
+                "id": "166428",
+                "color": [
+                  "green",
+                  "red"
+                ]
+              }
+            ]
+            "###);
+        })
+        .await;
+
+    let (task, _status_code) =
+        index.update_settings(json!({ "filterableAttributes": ["title"] })).await;
+    let r = index.wait_task(task.uid()).await.succeeded();
+    snapshot!(r["status"], @r###""succeeded""###);
+
+    index
+        .search(json!({"q": "Dragon"}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(json_string!(response["hits"]), @r###"
+                [
+                  {
+                    "title": "How to Train Your Dragon: The Hidden World",
+                    "id": "166428",
+                    "color": [
+                      "green",
+                      "red"
+                    ]
+                  }
+                ]
+                "###);
+        })
+        .await;
+
+    let (task, _status_code) = index.update_settings(json!({ "filterableAttributes": [] })).await;
+    let r = index.wait_task(task.uid()).await.succeeded();
+    snapshot!(r["status"], @r###""succeeded""###);
+
+    index
+        .search(json!({"q": "Dragon"}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(json_string!(response["hits"]), @r###"
+                    [
+                      {
+                        "title": "How to Train Your Dragon: The Hidden World",
+                        "id": "166428",
+                        "color": [
+                          "green",
+                          "red"
+                        ]
+                      }
+                    ]
+                    "###);
+        })
+        .await;
+}

From 5d191c479e0f328ca670be5803fc4cbaeb967c0e Mon Sep 17 00:00:00 2001
From: ManyTheFish <many@meilisearch.com>
Date: Thu, 12 Jun 2025 12:37:27 +0200
Subject: [PATCH 2/2] Skip indexing on settings update when possible,

when removing a field from the filterable settings,
this will trigger a reindexing of the negative version of the document,
which removes the document from the searchable as well because the field was considered removed.
---
 .../extract/extract_docid_word_positions.rs                | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs b/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
index d502e69cc..b906c7778 100644
--- a/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
+++ b/crates/milli/src/update/index_documents/extract/extract_docid_word_positions.rs
@@ -29,7 +29,6 @@ pub fn extract_docid_word_positions<R: io::Read + io::Seek>(
     let max_positions_per_attributes = max_positions_per_attributes
         .map_or(MAX_POSITION_PER_ATTRIBUTE, |max| max.min(MAX_POSITION_PER_ATTRIBUTE));
     let max_memory = indexer.max_memory_by_thread();
-    let force_reindexing = settings_diff.reindex_searchable();
 
     // initialize destination values.
     let mut documents_ids = RoaringBitmap::new();
@@ -43,6 +42,12 @@ pub fn extract_docid_word_positions<R: io::Read + io::Seek>(
         true,
     );
 
+    let force_reindexing = settings_diff.reindex_searchable();
+    let skip_indexing = !force_reindexing && settings_diff.settings_update_only();
+    if skip_indexing {
+        return sorter_into_reader(docid_word_positions_sorter, indexer);
+    }
+
     // initialize buffers.
     let mut del_buffers = Buffers::default();
     let mut add_buffers = Buffers::default();