Re: [PATCH 2/2] comdlg32: Delay OleInitialize() for Windows versions older than Vista.

[Alexandre Julliard]

Józef Kucia  writes:
> This fixes a regression introduced by commit
> f65e04770dc5748521a0de73814cea0b085bf3f8.
>
> OleInitialize() creates a window for the main apartment. SimCity 2000
> expects that the first created window after GetOpenFileA() is a file
> dialog window. According to tests, this is expected to work on Windows
> versions before Windows Vista.
>
> Signed-off-by: Józef Kucia

Is a version check really necessary? Couldn't we find some better way?
In what way does the app depend on the window creation order?

[PATCH 2/2] comdlg32: Delay OleInitialize() for Windows versions older than Vista.

[Józef Kucia]

On Wed, Feb 1, 2017 at 7:15 PM, Alexandre Julliard  wrote:
> Is a version check really necessary? Couldn't we find some better way?
> In what way does the app depend on the window creation order?

I think we may delay OleInitialize() unconditionally, but there is a
small risk we'll find an application which depends on the behavior of
newer Windows versions. An app to be affected by this change would
have to use hooks or similar mechanism, because the change won't be
visible in OFNHookProc.

The broken app installs WH_CBT hook, and it uses this hook to add HWND
handles to internal hashmap-like data structure. When a file dialog
window is not reported to the hook procedure as the first window
created immediately after GetOpenFileName(), then it doesn't seem to
be added to this internal data structure, and the app crashes later on
in the file dialog lpfnHook when it cannot find HWND in its internal
data structure.

[PATCH 2/2] comdlg32: Delay OleInitialize() for Windows versions older than Vista.

[Alexandre Julliard]

Józef Kucia  writes:
> On Wed, Feb 1, 2017 at 7:15 PM, Alexandre Julliard  wrote:
> > Is a version check really necessary? Couldn't we find some better way?
> > In what way does the app depend on the window creation order?
>
> I think we may delay OleInitialize() unconditionally, but there is a
> small risk we'll find an application which depends on the behavior of
> newer Windows versions. An app to be affected by this change would
> have to use hooks or similar mechanism, because the change won't be
> visible in OFNHookProc.

Yes, we can probably try that, at least until we find an app that
breaks.