Re: emacs 23.0.60.1 built today (11th feb 2008) crashes under Vista

[Eli Zaretskii]

> Date: Thu, 14 Feb 2008 08:32:17 +0000
> From: Jason Rumney <address@hidden>
> Cc: address@hidden
> 
> > I am happy to report that Emacs does indeed not crash on Vista after 
> > reverting the changes to w32.c, using the method suggested by Juanma. 
> > Hopefully a proper fix (because I assume the changes I reverted have 
> > some purpose too) isn't too hard to do.
> 
> One possibility is that user_sid is not large enough to hold the sub 
> authorities on Vista. One way to check this is to look at the value of 
> trash in init_user_info just before the crash occurs. That should 
> contain the size that was required. This code could all be written more 
> robustly, checking the size and using alloca to temporarily allocate a 
> larger buffer where necessary.

I never liked the way that code casts structures to `PSID *', as in

      lookup_account_sid (NULL, *((PSID *) user_sid), name, &length,

This smells of abusing some object by a subtly incompatible pointer.
But that's how that part of the code was written before me, and it
worked on XP and saved me yet another dance with a function that needs
to be called via a pointer after loading a DLL.

Hopefully, the program I sent earlier, if it doesn't crash on Vista,
will give me enough information to rewrite that code in a more robust
way.