From 52f078580e47fdfc83ce0fe3c9cffb967b77cfba Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Tue, 14 Apr 2026 12:45:29 +0300
Subject: [PATCH] cgen: Can't spread rlock-ed shared variable (fixes #17273)

---
 vlib/v/gen/c/array.v                               |  6 +-----
 vlib/v/gen/c/struct.v                              |  6 +-----
 .../v/tests/structs/struct_init_with_update_test.v | 14 ++++++++++++++
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/vlib/v/gen/c/array.v b/vlib/v/gen/c/array.v
index b588b63db..5f27fa2eb 100644
--- a/vlib/v/gen/c/array.v
+++ b/vlib/v/gen/c/array.v
@@ -2319,11 +2319,7 @@ fn (mut g Gen) fixed_array_update_expr_field(expr_str string, field_type ast.Typ
 		} else {
 			g.write(expr_str)
 			if !expr_str.ends_with(']') {
-				if field_type.is_ptr() {
-					g.write('->')
-				} else {
-					g.write('.')
-				}
+				g.write(g.dot_or_ptr(field_type))
 				if is_update_embed {
 					g.write(embed_field)
 				}
diff --git a/vlib/v/gen/c/struct.v b/vlib/v/gen/c/struct.v
index 9deda9c53..06dacfc04 100644
--- a/vlib/v/gen/c/struct.v
+++ b/vlib/v/gen/c/struct.v
@@ -385,11 +385,7 @@ fn (mut g Gen) struct_init(node ast.StructInit) {
 					}
 				}
 				if !is_arr_fixed {
-					if node.update_expr_type.is_ptr() {
-						g.write('->')
-					} else {
-						g.write('.')
-					}
+					g.write(g.dot_or_ptr(node.update_expr_type))
 					if node.is_update_embed {
 						g.write(g.get_embed_field_name(node.update_expr_type, field.name))
 					}
diff --git a/vlib/v/tests/structs/struct_init_with_update_test.v b/vlib/v/tests/structs/struct_init_with_update_test.v
index a14c65fce..cdb23d26f 100644
--- a/vlib/v/tests/structs/struct_init_with_update_test.v
+++ b/vlib/v/tests/structs/struct_init_with_update_test.v
@@ -46,3 +46,17 @@ fn test_struct_init_with_update_expr2() {
 	assert b.s == 'AA'
 	assert b.n == 3
 }
+
+struct SharedSpreadAbc {
+	a string
+}
+
+fn test_struct_init_with_update_expr_from_rlock_shared_value() {
+	shared abc := SharedSpreadAbc{'a'}
+	abc_clone := rlock abc {
+		SharedSpreadAbc{
+			...abc
+		}
+	}
+	assert abc_clone == SharedSpreadAbc{'a'}
+}
-- 
2.39.5