Re: dlls/opengl32/wgl.c: minor dealloc fix

[Stefan Dösinger]

Am 01.01.2007 um 11:03 schrieb Nick Burns:
> There can be a problem where the detach is hit before  
> internal_gl_extensions is allocated and it tries to free NULL and  
> dies...
>
> This just checks for the allocation before freeing -- very minor
> - Nick

HeapFree(GetProcessHeap(), 0, NULL) is supposed to be a nop, so the  
check is not needed.

dlls/opengl32/wgl.c: minor dealloc fix

[Nick Burns]

According to...
    http://msdn2.microsoft.com/en-us/library/aa366701.aspx

lpMem
   [in] ...If this pointer is NULL, the behavior is undefined.

I personally dislike undefined behaviour -- If it is defined to NOP in wine 
that is sufficent for me.

But I think/tought I had a crash there tho...

- Nick
> From: Stefan Dösinger 
> To: [e-mail]
> CC: Nick Burns 
> Subject: Re: dlls/opengl32/wgl.c: minor dealloc fix
> Date: Mon, 1 Jan 2007 22:33:49 +0100
>
> Am 01.01.2007 um 11:03 schrieb Nick Burns:
> > There can be a problem where the detach is hit before  
> > internal_gl_extensions is allocated and it tries to free NULL and  dies...
> >
> > This just checks for the allocation before freeing -- very minor
> > - Nick
>
> HeapFree(GetProcessHeap(), 0, NULL) is supposed to be a nop, so the  check 
> is not needed.

dlls/opengl32/wgl.c: minor dealloc fix

[Stefan Dösinger]

Am 02.01.2007 um 00:54 schrieb Nick Burns:
> According to...
>    http://msdn2.microsoft.com/en-us/library/aa366701.aspx
>
> lpMem
>   [in] ...If this pointer is NULL, the behavior is undefined.
>
> I personally dislike undefined behaviour -- If it is defined to NOP  
> in wine that is sufficent for me.
>
> But I think/tought I had a crash there tho...

I think we have a test case for that, as well as a test case for  
allocation of 0 bytes. Not sure about the details though, but there  
was a series of patches before to remove such checks.
> - Nick
> > From: Stefan Dösinger 
> > To: [e-mail]
> > CC: Nick Burns 
> > Subject: Re: dlls/opengl32/wgl.c: minor dealloc fix
> > Date: Mon, 1 Jan 2007 22:33:49 +0100
> >
> > Am 01.01.2007 um 11:03 schrieb Nick Burns:
> > > There can be a problem where the detach is hit before   
> > > internal_gl_extensions is allocated and it tries to free NULL  
> > > and  dies...
> > >
> > > This just checks for the allocation before freeing -- very minor
> > > - Nick
> >
> > HeapFree(GetProcessHeap(), 0, NULL) is supposed to be a nop, so  
> > the  check is not needed.

dlls/opengl32/wgl.c: minor dealloc fix

[Vitaliy Margolen]

DO NOT top post bottom posted emails!!!
Nick Burns wrote:
> > From: Stefan Dösinger 
> > To: [e-mail]
> > CC: Nick Burns 
> > Subject: Re: dlls/opengl32/wgl.c: minor dealloc fix
> > Date: Mon, 1 Jan 2007 22:33:49 +0100
> >
> > Am 01.01.2007 um 11:03 schrieb Nick Burns:
> > > There can be a problem where the detach is hit before 
> > > internal_gl_extensions is allocated and it tries to free NULL and 
> > > dies...
> > >
> > > This just checks for the allocation before freeing -- very minor
> > > - Nick
> >
> > HeapFree(GetProcessHeap(), 0, NULL) is supposed to be a nop, so the 
> > check is not needed.
>
> According to...
>    http://msdn2.microsoft.com/en-us/library/aa366701.aspx
>
> lpMem
>   [in] ...If this pointer is NULL, the behavior is undefined.

That's incorrect. 90% of MSDN is not correct or incomplete. The behavior
is well known and defined (at least in Wine) - NULL pointers are ignored.

So your patch is not correct.

Vitaliy.

dlls/opengl32/wgl.c: minor dealloc fix

[Nick Burns]

Got ya, -- looking at the heapfree impl -- it does the check first (so it is 
defined in Wine)

-- So please ignore this patch then --

However, this seems dangerous if you wanted to take any of that code and run 
it under windows (but im guessing xp and 2k work this way -- and few people 
use 95/98/me anymore)

Where is a good place for api docs other than the MSDN? (and no source does 
not count as good api docs)

It seems like Microsoft should be notified of incorrect/incomplete api docs 
-- so they can correct them
(but sadly this is a huge thankless task...)

- Nick
> From: Vitaliy Margolen 
> To: Nick Burns 
> CC: [e-mail]
> Subject: Re: dlls/opengl32/wgl.c: minor dealloc fix
> Date: Mon, 01 Jan 2007 18:00:44 -0700
>
> DO NOT top post bottom posted emails!!!
> Nick Burns wrote:
> > > From: Stefan Dösinger 
> > > To: [e-mail]
> > > CC: Nick Burns 
> > > Subject: Re: dlls/opengl32/wgl.c: minor dealloc fix
> > > Date: Mon, 1 Jan 2007 22:33:49 +0100
> > >
> > > Am 01.01.2007 um 11:03 schrieb Nick Burns:
> > > > There can be a problem where the detach is hit before
> > > > internal_gl_extensions is allocated and it tries to free NULL and
> > > > dies...
> > > >
> > > > This just checks for the allocation before freeing -- very minor
> > > > - Nick
> > >
> > > HeapFree(GetProcessHeap(), 0, NULL) is supposed to be a nop, so the
> > > check is not needed.
> >
> > According to...
> >    http://msdn2.microsoft.com/en-us/library/aa366701.aspx
> >
> > lpMem
> >   [in] ...If this pointer is NULL, the behavior is undefined.
>
> That's incorrect. 90% of MSDN is not correct or incomplete. The behavior
> is well known and defined (at least in Wine) - NULL pointers are ignored.
>
> So your patch is not correct.
>
> Vitaliy.

dlls/opengl32/wgl.c: minor dealloc fix

[Kai Blin]

On Tuesday 02 January 2007 02:40, Nick Burns wrote:
> However, this seems dangerous if you wanted to take any of that code and
> run it under windows (but im guessing xp and 2k work this way -- and few
> people use 95/98/me anymore)

There are win98 tests run on test.winehq.org. You can check there if the 
HeapFree() works there.
> Where is a good place for api docs other than the MSDN? (and no source does
> not count as good api docs)

I'm afraid the Wine source is the most complete win32 api doc apart from MSDN.
> It seems like Microsoft should be notified of incorrect/incomplete api docs
> -- so they can correct them
> (but sadly this is a huge thankless task...)

I sort of doubt they'll fix it for us. They didn't fix it for the EU.

Cheers,
Kai