From f6473177e5f64cf442f6fa411027ad0b20382139 Mon Sep 17 00:00:00 2001
From: Yurii Karabas <1998uriyyo@gmail.com>
Date: Tue, 5 Aug 2025 11:12:45 +0200
Subject: [PATCH] Simplify fields to extract calculation

---
 fastapi/dependencies/utils.py | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/fastapi/dependencies/utils.py b/fastapi/dependencies/utils.py
index baf226b7a..58cb9f36c 100644
--- a/fastapi/dependencies/utils.py
+++ b/fastapi/dependencies/utils.py
@@ -750,20 +750,16 @@ def request_params_to_args(
     if not fields:
         return values, errors
 
-    fields_to_extract = fields
     default_convert_underscores = True
 
     params_to_process: Dict[str, Any] = {}
 
-    model_fields = [
-        field for field in fields if lenient_issubclass(field.type_, BaseModel)
+    fields_to_extract = [
+        cached_field
+        for field in fields
+        if lenient_issubclass(field.type_, BaseModel)
+        for cached_field in get_cached_model_fields(field.type_)
     ]
-    if model_fields:
-        fields_to_extract = [
-            cached_field
-            for field in model_fields
-            for cached_field in get_cached_model_fields(field.type_)
-        ]
 
     processed_keys = set()