[vala/staging] vala: Don't replace assignments for local variables with non-null simple-types

[Rico Tzschichholz <ricotz src gnome org>]

commit 1f885e91cb196b9f03586e88ec56c8c8995919c3
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Thu Nov 22 12:40:23 2018 +0100

    vala: Don't replace assignments for local variables with non-null simple-types
    
    Reintroduce e701142da4601ece5ca71cc4484728b08969c74e
    
    See https://gitlab.gnome.org/GNOME/vala/issues/755

 vala/valaassignment.vala | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)
---
diff --git a/vala/valaassignment.vala b/vala/valaassignment.vala
index 0b6fbc9ad..183ea57be 100644
--- a/vala/valaassignment.vala
+++ b/vala/valaassignment.vala
@@ -224,13 +224,13 @@ public class Vala.Assignment : Expression {
                        return false;
                }
 
-               if (operator != AssignmentOperator.SIMPLE && left is MemberAccess) {
+               unowned MemberAccess? ma = left as MemberAccess;
+               if (operator != AssignmentOperator.SIMPLE && ma != null
+                   && !(left.value_type.is_non_null_simple_type () && ma.symbol_reference is LocalVariable)) 
{
                        // transform into simple assignment
                        // FIXME: only do this if the backend doesn't support
                        // the assignment natively
 
-                       var ma = (MemberAccess) left;
-
                        var old_value = new MemberAccess (ma.inner, ma.member_name);
 
                        BinaryOperator bop;
@@ -260,9 +260,7 @@ public class Vala.Assignment : Expression {
                        operator = AssignmentOperator.SIMPLE;
                }
 
-               if (left is MemberAccess) {
-                       var ma = (MemberAccess) left;
-
+               if (ma != null) {
                        if (ma.symbol_reference is Property) {
                                var prop = (Property) ma.symbol_reference;