[PATCH] kernel32: return copy of environment blockinGetEnvironmentStringsW

[Dmitry Timoshkov]

"Peter Beutner" <p.beutner at gmx.net> wrote:

>> Probably an exception handler should be added inside of RtlFreeHeap
>> instead.
> hm, i vaguely remember reading here that it was prefered not to cover up
> crashes produced by passing invalid pointers, unless absolutely necessary.

If the crash is caused by a NULL pointer then the fix is easy and doesn't
require using an exception handler, but it's not possible in this case.

> And here we can fix that nicely in some other way.
> See attached patch. Would that be acceptable as well?
> 
> diff --git a/dlls/kernel32/environ.c b/dlls/kernel32/environ.c
> index 414ccbf..f7890cc 100644
> --- a/dlls/kernel32/environ.c
> +++ b/dlls/kernel32/environ.c
> @@ -148,6 +148,10 @@ LPWSTR WINAPI GetEnvironmentStringsW(void)
>  */
> BOOL WINAPI FreeEnvironmentStringsA( LPSTR ptr )
> {
> +    /* broken app passes ptr it got from GetEnvironmentStringsW */
> +    if(ptr == NtCurrentTeb()->Peb->ProcessParameters->Environment)
> +        return TRUE;
> +
>     return HeapFree( GetProcessHeap(), 0, ptr );
> }

Personally I think that adding an exception handler or probably just a more
strict consistency check inside of RtlFreeHeap should be better.

-- 
Dmitry.