[PATCH v2 0/1] MR4786: win32u: Query virtual desktop status from the registry.

[Zhiyi Zhang (＠zhiyi)]

Checking flags of the thread desktop to determine whether virtual desktop is on is unreliable.
For example, CEF applications create their own desktop and so is_virtual_desktop() could incorrectly
report that virtual desktop is off.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55810

--
  v2: server: inherit DF_WINE_CREATE_DESKTOP when creating a non-root desktop.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4786

[PATCH v2 1/1] server: inherit DF_WINE_CREATE_DESKTOP when creating a non-root desktop.

[Zhiyi Zhang]

From: Zhiyi Zhang <zzhang(a)codeweavers.com>

Based on Rémi's idea.

CEF applications create their own desktops and so is_virtual_desktop() could incorrectly
report that virtual desktop is off if DF_WINE_CREATE_DESKTOP is not inherited.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55810
---
 server/winstation.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/server/winstation.c b/server/winstation.c
index 5903497d61e..4d187b78b10 100644
--- a/server/winstation.c
+++ b/server/winstation.c
@@ -221,14 +221,27 @@ struct desktop *get_desktop_obj( struct process *process, obj_handle_t handle, u
 static struct desktop *create_desktop( const struct unicode_str *name, unsigned int attr,
                                        unsigned int flags, struct winstation *winstation )
 {
-    struct desktop *desktop;
+    static const WCHAR rootW[] = {'r','o','o','t'};
+    struct desktop *desktop, *current_desktop;
 
     if ((desktop = create_named_object( &winstation->obj, &desktop_ops, name, attr, NULL )))
     {
         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
         {
             /* initialize it if it didn't already exist */
-            desktop->flags = flags;
+
+            /* inherit DF_WINE_CREATE_DESKTOP when creating a non-root desktop */
+            if ((name->len != sizeof(rootW) || memcmp( name->str, rootW, name->len ))
+                && (current_desktop = get_thread_desktop( current, 0 )))
+            {
+                desktop->flags = flags | (current_desktop->flags & DF_WINE_CREATE_DESKTOP);
+                release_object( current_desktop );
+            }
+            else
+            {
+                desktop->flags = flags;
+            }
+
             desktop->winstation = (struct winstation *)grab_object( winstation );
             desktop->top_window = NULL;
             desktop->msg_window = NULL;
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/4786

[PATCH v2 0/1] MR4786: win32u: Query virtual desktop status from the registry. - approved

[Rémi Bernon]

This merge request was approved by Rémi Bernon.
-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4786

[Alexandre Julliard (＠julliard)]

I don't think the server should know about the 'root' name, or check the name at all, particularly if we consider that the desktop is being created from non-Wine code.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4786#note_56886

[Rémi Bernon]

So I guess instead we could have another private `DF_WINE_USE_ROOT_WINDOW` flag or something, that `explorer.exe` would use, and we would inherit desktop flags only if neither private flags are set?

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/4786#note_56887