parser: a small immutable field fix

compiler/parser.v

@@ -2179,9 +2179,8 @@ fn (p mut Parser) dot(str_typ_ string, method_ph int) string {
 		next := p.peek()
 		modifying := next.is_assign() || next == .inc || next == .dec ||
 			(field.typ.starts_with('array_') && next == .left_shift)
-		is_vi := p.fileis('vid')
+		if !p.builtin_mod && !p.pref.translated && modifying &&
-		if !p.builtin_mod && !p.pref.translated && modifying && !is_vi
+			p.has_immutable_field {
-			&& p.has_immutable_field {
 			f := p.first_immutable_field
 			p.error_with_token_index('cannot modify immutable field `$f.name` (type `$f.parent_fn`)\n' +
 					'declare the field with `mut:`
@@ -2190,8 +2189,6 @@ struct $f.parent_fn {
 	$f.name $f.typ
 }
 ', fname_tidx)
-		}
-		if !p.builtin_mod && p.mod != typ.mod {
 		}
 		// Don't allow `arr.data`
 		if field.access_mod == .private && !p.builtin_mod && !p.pref.translated && p.mod != typ.mod {

compiler/tests/struct_test.v

@@ -107,3 +107,14 @@ fn test_reserved_keywords() {
 	assert rk_holder2.volatile == 11
 	assert rk_holder2.while == 0 //Zero value as not specified.
 }
+
+struct User2 {
+mut:
+	name string
+}	
+
+fn test_mutable_fields() {
+	mut u := User2{}
+	u.name = 'Peter'
+	assert u.name == 'Peter'
+}	

vlib/os/os_nix.v

@@ -9,7 +9,7 @@ const (
 
 fn init_os_args(argc int, argv &byteptr) []string {
 	mut args := []string
-	for i := 0; i < argc; i++ {
+	for i in 0 .. argc {
 		args << string(argv[i])
 	}		
 	return args