[Spice-devel] [spice-gtk 2/9] widget: Do not mix function linkage

[Frediano Ziglio]

> 
> Hi
> 
> On Wed, Jun 8, 2016 at 1:10 PM, Frediano Ziglio <fziglio at redhat.com> wrote:
> > This prevents a possible crash on windows 32 bit.
> > The linkage of UnhookWindowsHookEx is WINAPI which is __stdcall while
> > callback for g_clear_pointer is C. This could cause stack pointer
> > corruption depending on compiler flags.
> >
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> 
> Reviewed-by: Marc-André Lureau <marcandre.lureau at redhat.com>
> 

Though this was simple enough to get an ack/nack...

Should I extend the comment to explain the background?

Frediano

> 
> > ---
> >  src/spice-widget.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/spice-widget.c b/src/spice-widget.c
> > index b5936bc..c528614 100644
> > --- a/src/spice-widget.c
> > +++ b/src/spice-widget.c
> > @@ -827,7 +827,11 @@ static void try_keyboard_ungrab(SpiceDisplay *display)
> >      SPICE_DEBUG("ungrab keyboard");
> >      gdk_keyboard_ungrab(GDK_CURRENT_TIME);
> >  #ifdef G_OS_WIN32
> > -    g_clear_pointer(&d->keyboard_hook, UnhookWindowsHookEx);
> > +    // do not use g_clear_pointer as Windows API have different linkage
> > +    if (d->keyboard_hook) {
> > +        UnhookWindowsHookEx(d->keyboard_hook);
> > +        d->keyboard_hook = NULL;
> > +    }
> >  #endif
> >      d->keyboard_grab_active = false;
> >      g_signal_emit(widget, signals[SPICE_DISPLAY_KEYBOARD_GRAB], 0, false);