cgen: fix .sort(), and .sorted() method calls, when array aliases are used as receivers (fix #20075) (#20081)

vlib/v/checker/fn.v

@@ -1649,7 +1649,7 @@ fn (mut c Checker) cast_to_fixed_array_ret(typ ast.Type, sym ast.TypeSymbol) ast
 	return typ
 }
 
-// checks if a type from another module is is expected and visible(`is_pub`)
+// checks if a type from another module is as expected and visible(`is_pub`)
 fn (mut c Checker) check_type_and_visibility(name string, type_idx int, expected_kind &ast.Kind, pos &token.Pos) bool {
 	mut sym := c.table.sym_by_idx(type_idx)
 	if sym.kind == .alias {

vlib/v/gen/c/array.v

@@ -590,9 +590,21 @@ fn (mut g Gen) gen_array_sorted(node ast.CallExpr) {
 	info := sym.info as ast.Array
 	depth := g.get_array_depth(info.elem_type)
 
+	deref_field := if node.receiver_type.nr_muls() > node.left_type.nr_muls()
+		&& node.left_type.is_ptr() {
+		true
+	} else {
+		false
+	}
+	if !deref_field {
 		g.write('${atype} ${past.tmp_var} = array_clone_to_depth(ADDR(${atype},')
 		g.expr(node.left)
 		g.writeln('), ${depth});')
+	} else {
+		g.write('${atype} ${past.tmp_var} = array_clone_to_depth(')
+		g.expr(node.left)
+		g.writeln(', ${depth});')
+	}
 
 	unsafe {
 		node.left = ast.Expr(ast.Ident{
@@ -708,7 +720,12 @@ fn (mut g Gen) gen_array_sort(node ast.CallExpr) {
 }
 
 fn (mut g Gen) gen_array_sort_call(node ast.CallExpr, compare_fn string) {
-	mut deref_field := g.dot_or_ptr(node.left_type)
+	deref_field := if node.receiver_type.nr_muls() > node.left_type.nr_muls()
+		&& node.left_type.is_ptr() {
+		g.dot_or_ptr(node.left_type.deref())
+	} else {
+		g.dot_or_ptr(node.left_type)
+	}
 	// eprintln('> qsort: pointer $node.left_type | deref_field: `$deref_field`')
 	g.empty_line = true
 	g.write('qsort(')

vlib/v/tests/array_methods_test.v

@@ -73,3 +73,15 @@ fn test_string_eq_method_with_interface() {
 	}
 	assert false
 }
+
+// test deref when alias as receiver of methods
+type Array = []int
+
+pub fn (mut arr Array) alias_as_receiver_deref() []int {
+	return arr.sorted(b < a)
+}
+
+fn test_alias_as_receiver_deref() {
+	mut arr := Array([1, 2, 3])
+	assert arr.alias_as_receiver_deref() == [3, 2, 1]
+}