[vlc-devel] [PATCH] qt: casting to children type in parent constructor is UB

[Rémi Denis-Courmont]

Le tiistaina 23. huhtikuuta 2019, 10.51.59 EEST Pierre Lamot a écrit :
>   children object isn't built yet.
> 
>   Fixes #22187
> ---
>  modules/gui/qt/adapters/variables.hpp | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/modules/gui/qt/adapters/variables.hpp
> b/modules/gui/qt/adapters/variables.hpp index 710880cf23..930a7e2238 100644
> --- a/modules/gui/qt/adapters/variables.hpp
> +++ b/modules/gui/qt/adapters/variables.hpp
> @@ -112,17 +112,13 @@ public:
>          , m_object(new VLCObjectHolderImpl<T>(nullptr))
>          , m_property(property)
>      {
> -        resetObject<T>(object);
> -        Derived* derived = static_cast<Derived*>(this);
> -        connect(derived, &Derived::valueChangedInternal, this,
> &QVLCVariable<Derived, BaseType>::onValueChangedInternal,
> Qt::QueuedConnection); }
> 
>      virtual ~QVLCVariable()
>      {
>          if (m_object->get())
>          {
> -            Derived* derived = static_cast<Derived*>(this);
> -            var_DelCallback(m_object->get(), qtu(m_property),
> value_modified, derived);
> +            var_DelCallback(m_object->get(),
> qtu(m_property), value_modified, this); var_Destroy(m_object->get(),
> qtu(m_property));

Uh... Doesn't this incorrectly assume that pointer fixup is unnecessary?

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