From f105a2224a5891ee8e1b3f9a31143165aef82429 Mon Sep 17 00:00:00 2001
From: Mubelotix <simon@meilisearch.com>
Date: Fri, 1 Aug 2025 11:04:48 +0200
Subject: [PATCH] Clarify fields_unused

Co-Authored-By: Louis Dureuil <louis.dureuil@xinra.net>
---
 crates/meilisearch/src/routes/indexes/render.rs | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/crates/meilisearch/src/routes/indexes/render.rs b/crates/meilisearch/src/routes/indexes/render.rs
index be495bb2b..6ac0a939c 100644
--- a/crates/meilisearch/src/routes/indexes/render.rs
+++ b/crates/meilisearch/src/routes/indexes/render.rs
@@ -490,15 +490,21 @@ async fn render(index: Index, query: RenderQuery) -> Result<RenderResult, Respon
         .input
         .as_ref()
         .is_some_and(|i| i.inline.as_ref().is_some_and(|i| i.get("fields").is_some()));
-    let fields_probably_used = template.as_str().is_none_or(|s| s.contains("fields"));
+    let fields_unused = match template.as_str() {
+        Some(template) => {
+            // might be a false positive if fields appear as a non-variable
+            // it is OK to be over-eager here, it will just translate to more work
+            !template.contains("fields")
+        }
+        None => true, // non-text templates cannot use `fields`
+    };
     let has_inline_doc = query
         .input
         .as_ref()
         .is_some_and(|i| i.inline.as_ref().is_some_and(|i| i.get("doc").is_some()));
     let has_document_id = query.input.as_ref().is_some_and(|i| i.document_id.is_some());
     let has_doc = has_inline_doc || has_document_id;
-    let insert_fields =
-        fields_available && has_doc && fields_probably_used && !fields_already_present;
+    let insert_fields = fields_available && has_doc && !fields_unused && !fields_already_present;
     if has_inline_doc && has_document_id {
         return Err(BothInlineDocAndDocId.into());
     }