From 6d8086747d67f32333cf21b28fb6b140a2758080 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Thu, 26 Feb 2026 10:02:42 +0300
Subject: [PATCH] checker: skip ref field init check when default expr exists
 (fixes #25213)

---
 vlib/v/checker/struct.v                          | 16 ++++++++++++----
 ..._struct_with_linked_list_of_refs_field_test.v | 12 ++++++++++++
 2 files changed, 24 insertions(+), 4 deletions(-)
 create mode 100644 vlib/v/tests/generics/generic_struct_with_linked_list_of_refs_field_test.v

diff --git a/vlib/v/checker/struct.v b/vlib/v/checker/struct.v
index 01ec407e5..3e35c1151 100644
--- a/vlib/v/checker/struct.v
+++ b/vlib/v/checker/struct.v
@@ -1226,8 +1226,12 @@ fn (mut c Checker) check_ref_fields_initialized(struct_sym &ast.TypeSymbol, mut
 		if field.typ in checked_types {
 			continue
 		}
-		if field.typ.is_ptr() && !field.typ.has_flag(.shared_f) && !field.typ.has_flag(.option)
-			&& !field.has_default_expr {
+		if field.has_default_expr {
+			// The field is already initialized by its default expression.
+			// Its nested reference fields should not be treated as missing.
+			continue
+		}
+		if field.typ.is_ptr() && !field.typ.has_flag(.shared_f) && !field.typ.has_flag(.option) {
 			c.error('reference field `${linked_name}.${field.name}` must be initialized (part of struct `${struct_sym.name}`)',
 				pos)
 			continue
@@ -1273,8 +1277,12 @@ fn (mut c Checker) check_ref_fields_initialized_note(struct_sym &ast.TypeSymbol,
 		if field.typ in checked_types {
 			continue
 		}
-		if field.typ.is_ptr() && !field.typ.has_flag(.shared_f) && !field.typ.has_flag(.option)
-			&& !field.has_default_expr {
+		if field.has_default_expr {
+			// The field is already initialized by its default expression.
+			// Its nested reference fields should not be treated as missing.
+			continue
+		}
+		if field.typ.is_ptr() && !field.typ.has_flag(.shared_f) && !field.typ.has_flag(.option) {
 			c.note('reference field `${linked_name}.${field.name}` must be initialized (part of struct `${struct_sym.name}`)',
 				pos)
 			continue
diff --git a/vlib/v/tests/generics/generic_struct_with_linked_list_of_refs_field_test.v b/vlib/v/tests/generics/generic_struct_with_linked_list_of_refs_field_test.v
new file mode 100644
index 000000000..d2f7a60ef
--- /dev/null
+++ b/vlib/v/tests/generics/generic_struct_with_linked_list_of_refs_field_test.v
@@ -0,0 +1,12 @@
+import datatypes
+
+struct OtherType {}
+
+struct SomeType {
+	cfg datatypes.LinkedList[&OtherType]
+}
+
+fn test_generic_struct_with_linked_list_of_refs_field() {
+	some_type := SomeType{}
+	assert some_type.cfg.len() == 0
+}
-- 
2.39.5