bug#6284: Crash in w32_wnd_proc at frame deletion

[Jason Rumney]

Lennart Borgman <lennart.borgman@gmail.com> writes:

> New patch. I missed one place in the previous patch and this just hit me.
>
> It is great running under the debugger and finally being able to find
> and fix those bugs I have wondered about quite long now but have not
> had time to fix before.
>
> The only problem now is how to get them installed. As I said elsewhere
> I currently have no checkout from savannah so I can't checkin the
> patches myself AFAIK. Should I get a second checkout from savannah for
> this, or?

I fixed the two locations where a bug could conceivably occur.  Others
were either #ifdef'ed out, or already protected against dereferencing
the non-existent frame struct.