1.1 --- a/src/BytecodeCompiler.cpp	Sun Sep 16 22:49:54 2012 -0700
     1.2 +++ b/src/BytecodeCompiler.cpp	Sun Sep 16 23:15:13 2012 -0700
     1.3 @@ -987,10 +987,17 @@
     1.4              }
     1.5          }
     1.6      } else if (type->isStruct()) {
     1.7 -        Local<Map> map(zone_, type->newMap());
     1.8 +        Local<StructMap> map(zone_, StructMap::cast(type->newMap()));
     1.9 +
    1.10 +        // Because structs can contain arrays, any sort of composition
    1.11 +        // triggers non-LIFO allocation. This is just for correctness.
    1.12 +        // We could do better by:
    1.13 +        //  (1) Limiting to structs that just (recursively) contain arrays,
    1.14 +        //  (2) Swap Stack for Default tenure in Struct::New
    1.15 +        //  (3) JIT analysis
    1.16          if (var->scope()->kind() == Scope::GLOBAL)
    1.17              __ newstruct(map, Heap::Tenure_Old);
    1.18 -        else if (var->needsHeapAllocation())
    1.19 +        else if (var->needsHeapAllocation() || map->composed())
    1.20              __ newstruct(map, Heap::Tenure_Default);
    1.21          else
    1.22              __ newstruct(map, Heap::Tenure_Stack);