checker: fix wrong overload operator checking for generic aliased type

vlib/v/checker/infix.v

@@ -354,12 +354,24 @@ fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 					} else {
 						return_type = right_type
 					}
-				} else if right_final_sym.has_method(node.op.str()) {
-					if method := right_final_sym.find_method(node.op.str()) {
+				} else if right_final_sym.has_method_with_generic_parent(node.op.str()) {
+					if method := right_final_sym.find_method_with_generic_parent(node.op.str()) {
 						return_type = method.return_type
 					} else {
 						return_type = right_type
 					}
+				} else if left_sym.has_method(node.op.str()) {
+					if method := left_sym.find_method(node.op.str()) {
+						return_type = method.return_type
+					} else {
+						return_type = left_type
+					}
+				} else if left_final_sym.has_method_with_generic_parent(node.op.str()) {
+					if method := left_final_sym.find_method_with_generic_parent(node.op.str()) {
+						return_type = method.return_type
+					} else {
+						return_type = left_type
+					}
 				} else {
 					left_name := c.table.type_to_str(unwrapped_left_type)
 					right_name := c.table.type_to_str(unwrapped_right_type)

vlib/v/tests/aliases/alias_with_op_overloading_test.v

@@ -0,0 +1,22 @@
+module main
+
+import math.vec
+
+type Vector3 = vec.Vec3[f32]
+
+pub fn calc(a Vector3, b Vector3) Vector3 {
+	f := a.normalize()
+	return f * a + a * f
+}
+
+fn test_main() {
+	a := Vector3{
+		x: 1
+		y: 2
+		z: 3
+	}
+	t := calc(a, a)
+	assert int(t.x) == 0
+	assert int(t.y) == 2
+	assert int(t.z) == 4
+}