Re: [ros-dev] [ros-diffs] [spetreolle] 41204: ChangeDisplaySettingsA and ChangeDisplaySettingsW should reset dmDriverExtra to 0.

[Ged]

This seems very strange

-----Original Message-----
From: [e-mail] [mailto:[e-mail]] On Behalf Of [e-mail]
Sent: 30 May 2009 13:23
To: [e-mail]
Subject: [ros-diffs] [spetreolle] 41204: ChangeDisplaySettingsA and ChangeDisplaySettingsW should reset dmDriverExtra to 0.

Author: spetreolle
Date: Sat May 30 16:23:20 2009
New Revision: 41204

URL: http://svn.reactos.org/svn/reactos?rev=41204&view=rev
Log:
ChangeDisplaySettingsA and ChangeDisplaySettingsW should reset dmDriverExtra to 0.

Modified:
    trunk/reactos/dll/win32/user32/misc/display.c

Modified: trunk/reactos/dll/win32/user32/misc/display.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/user32/misc/displ...
==============================================================================
--- trunk/reactos/dll/win32/user32/misc/display.c [iso-8859-1] (original)
+++ trunk/reactos/dll/win32/user32/misc/display.c [iso-8859-1] Sat May 30 16:23:20 2009
@@ -493,7 +493,10 @@
   LPDEVMODEA lpDevMode,
   DWORD dwflags)
 {
-  return ChangeDisplaySettingsExA ( NULL, lpDevMode, NULL, dwflags, 0 );
+  LONG Status = ChangeDisplaySettingsExA ( NULL, lpDevMode, NULL, dwflags, 0 );
+  if(lpDevMode)
+    lpDevMode->dmDriverExtra = 0;
+  return Status;
 }

@@ -533,5 +536,8 @@
   LPDEVMODEW lpDevMode,
   DWORD dwflags)
 {
-  return ChangeDisplaySettingsExW ( NULL, lpDevMode, NULL, dwflags, 0 );
-}
+  LONG Status = ChangeDisplaySettingsExW ( NULL, lpDevMode, NULL, dwflags, 0 );
+  if(lpDevMode)
+    lpDevMode->dmDriverExtra = 0; 
+  return Status;
+}

[James Tabor]

Yes it is,,,,, I think to be more correct! The check is done prior to
calling ChangeDisplaySettingsEx not after....

On Sat, May 30, 2009 at 7:37 AM, Ged [e-mail] wrote:
> This seems very strange
> LPDEVMODEA lpDevMode,
>   DWORD dwflags)
>  {
> return ChangeDisplaySettingsExA ( NULL, lpDevMode, NULL, dwflags, 0 );
> LONG Status = ChangeDisplaySettingsExA ( NULL, lpDevMode, NULL, dwflags, 0 );
> if(lpDevMode)
> lpDevMode->dmDriverExtra = 0;
> return Status;
>
> }
>   LPDEVMODEW lpDevMode,
>   DWORD dwflags)
>  {
> return ChangeDisplaySettingsExW ( NULL, lpDevMode, NULL, dwflags, 0 );
>
> -}
> LONG Status = ChangeDisplaySettingsExW ( NULL, lpDevMode, NULL, dwflags, 0 );
> if(lpDevMode)
> lpDevMode->dmDriverExtra = 0;
> return Status;
>
> +}

[James Tabor]

Hi!
Wow! Good job Sylvain!! It works! You don't need to clear out the size
"dmDriverExtra"  after reseting it from ChangeDisplaySettingsEx. It
works now since we do not fully support it yet. I did add a test in
our win32k code when building the pdevobj, it looks for it from the
driver but does nothing.... Sorry for not pointing this out to you
earlier.

This is from wine, it's  good example:

/***********************************************************************
 *              ChangeDisplaySettingsW (USER32.@)
 */
LONG WINAPI ChangeDisplaySettingsW( LPDEVMODEW devmode, DWORD flags )
{
    if (devmode) devmode->dmDriverExtra = 0;

return ChangeDisplaySettingsExW(NULL,devmode,NULL,flags,NULL);
}

You do not need dmDriverExtra, it will reset during the call..... Wine
test must rely on this behavior to pass. If the call to
ChangeDisplaySettingsEx fails and it must check to see if
dmDriverExtra is zeroed. So ATM it must pass the way you have written
it. It is zeroed regardless and we do not support it.

Thanks,
James