From 7b22bae12ea108ee51a457a9dd99935ad0c88dc1 Mon Sep 17 00:00:00 2001
From: kbkpbot <kbkpbot@sina.com>
Date: Sat, 10 Jan 2026 02:01:09 +0800
Subject: [PATCH] cgen: fix generic function error propagation type mismatch
 (fix #26263) (#26295)

---
 vlib/v/gen/c/cgen.v                               | 15 ++++++++++++---
 .../generic_function_error_propagation_test.v     | 12 ++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 vlib/v/tests/generics/generic_function_error_propagation_test.v

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index b61a173e6..def0c3f12 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -7500,13 +7500,22 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type ast.Ty
 			if g.fn_decl == unsafe { nil } || g.fn_decl.return_type == ast.void_type {
 				g.writeln('\treturn;')
 			} else {
-				styp := g.styp(g.fn_decl.return_type)
+				mut fn_return_type := g.fn_decl.return_type
+				if g.cur_fn != unsafe { nil } && g.cur_fn.generic_names.len > 0
+					&& g.cur_concrete_types.len > 0 {
+					if converted_type := g.table.convert_generic_type(g.fn_decl.return_type,
+						g.cur_fn.generic_names, g.cur_concrete_types)
+					{
+						fn_return_type = converted_type
+					}
+				}
+				styp := g.styp(fn_return_type)
 				err_obj := g.new_tmp_var()
 				g.writeln('\t${styp} ${err_obj} = {0};')
-				if g.fn_decl.return_type.has_flag(.result) {
+				if fn_return_type.has_flag(.result) {
 					g.writeln('\t${err_obj}.is_error = true;')
 					g.writeln('\t${err_obj}.err = ${cvar_name}${tmp_op}err;')
-				} else if g.fn_decl.return_type.has_flag(.option) {
+				} else if fn_return_type.has_flag(.option) {
 					g.writeln('\t${err_obj}.state = 2;')
 				}
 				g.writeln('\treturn ${err_obj};')
diff --git a/vlib/v/tests/generics/generic_function_error_propagation_test.v b/vlib/v/tests/generics/generic_function_error_propagation_test.v
new file mode 100644
index 000000000..a2748ee37
--- /dev/null
+++ b/vlib/v/tests/generics/generic_function_error_propagation_test.v
@@ -0,0 +1,12 @@
+import rand
+
+type Condition = fn () bool
+
+fn test_generic_function_error_propagation() {
+	mut list := []Condition{}
+	list = [fn () bool {
+		return true
+	}]
+	println(rand.element[Condition](list) or { panic('Err') })
+	println(list)
+}
-- 
2.39.5