[PATCH v3 0/5] MR6944: winex11: Workaround KWin bug with maximized windows.

[Rémi Bernon]

I know we've had a policy to avoid window manager specific workarounds, I think we could reconsider it. The fix could be unguarded and applied with every window manager, and could very well work, but I think it is ugly enough to justify checking for KWin specifically.

The problem is that as soon as a window configure request is sent to a maximized window, KWin internal state gets bogus and it loses track of the window maximized state. I've described the KWin source details on https://bugs.kde.org/show_bug.cgi?id=496966 and opened https://invent.kde.org/plasma/kwin/-/merge_requests/6854 as a possible fix for it, but the time it will take to land could justify working around it in Wine.

The workaround is to avoid sending configure requests to maximized windows, which sounds sensible and we already avoid resizing maximized windows, but, moving a maximized window to a different monitor *requires* sending a configure request. KWin bug makes no difference to requests with only position changes, and they trigger it all the same. So, the only solution is to temporarily remove the maximized state bits before sending the configure request, putting them back afterwards. This is quite straightforward to do with the new state tracker, but it could very well trigger other problems with other window managers.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=57465

--
  v3: winex11: Workaround KWin bug with maximized windows.
      winex11: Keep track of the window manager name.
      winex11: Keep track of the _NET_SUPPORTING_WM_CHECK window.
      winex11: Listen to root window _NET_SUPPORTED property changes.
      winex11: Move the _NET_SUPPORTED information to the thread data.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6944

[PATCH v3 1/5] winex11: Move the _NET_SUPPORTED information to the thread data.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

---
 dlls/winex11.drv/window.c      | 31 +++++++++++++++++--------------
 dlls/winex11.drv/x11drv.h      |  5 +++++
 dlls/winex11.drv/x11drv_main.c |  2 ++
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index b99c96f644b..e35a3ff1873 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -104,11 +104,6 @@ static XContext host_window_context = 0;
 static Time last_user_time;
 static Window user_time_window;
 
-/* list of _NET_SUPPORTED atoms */
-static Atom *net_supported;
-static int net_supported_count;
-static UINT net_wm_state_mask;
-
 static const WCHAR whole_window_prop[] =
     {'_','_','w','i','n','e','_','x','1','1','_','w','h','o','l','e','_','w','i','n','d','o','w',0};
 static const WCHAR clip_window_prop[] =
@@ -1218,7 +1213,7 @@ static void window_set_net_wm_state( struct x11drv_win_data *data, UINT new_stat
 {
     UINT i, count, old_state = data->pending_state.net_wm_state;
 
-    new_state &= net_wm_state_mask;
+    new_state &= x11drv_thread_data()->net_wm_state_mask;
     data->desired_state.net_wm_state = new_state;
     if (!data->whole_window) return; /* no window, nothing to update */
     if (data->wm_state_serial) return; /* another WM_STATE update is pending, wait for it to complete */
@@ -3271,10 +3266,15 @@ LRESULT X11DRV_WindowMessage( HWND hwnd, UINT msg, WPARAM wp, LPARAM lp )
  */
 static BOOL is_netwm_supported( Atom atom )
 {
+    struct x11drv_thread_data *data = x11drv_thread_data();
+    BOOL supported;
     int i;
-    for (i = 0; i < net_supported_count; i++)
-        if (net_supported[i] == atom) return TRUE;
-    return FALSE;
+
+    for (i = 0; i < data->net_supported_count; i++)
+        if (data->net_supported[i] == atom) break;
+    supported = i < data->net_supported_count;
+
+    return supported;
 }
 
 
@@ -3400,22 +3400,25 @@ void X11DRV_FlashWindowEx( FLASHWINFO *pfinfo )
     release_win_data( data );
 }
 
-void init_win_context(void)
+void net_supported_init( struct x11drv_thread_data *data )
 {
     unsigned long count, remaining;
     int format, i;
     Atom type;
 
-    if (!XGetWindowProperty( gdi_display, DefaultRootWindow( gdi_display ), x11drv_atom(_NET_SUPPORTED), 0, 65536 / sizeof(CARD32),
-                             False, XA_ATOM, &type, &format, &count, &remaining, (unsigned char **)&net_supported ))
-        net_supported_count = get_property_size( format, count ) / sizeof(Atom);
+    if (!XGetWindowProperty( data->display, DefaultRootWindow( data->display ), x11drv_atom(_NET_SUPPORTED), 0, 65536 / sizeof(CARD32),
+                             False, XA_ATOM, &type, &format, &count, &remaining, (unsigned char **)&data->net_supported ))
+        data->net_supported_count = get_property_size( format, count ) / sizeof(Atom);
 
     for (i = 0; i < NB_NET_WM_STATES; i++)
     {
         Atom atom = X11DRV_Atoms[net_wm_state_atoms[i] - FIRST_XATOM];
-        if (is_netwm_supported( atom )) net_wm_state_mask |= (1 << i);
+        if (is_netwm_supported( atom )) data->net_wm_state_mask |= (1 << i);
     }
+}
 
+void init_win_context(void)
+{
     init_recursive_mutex( &win_data_mutex );
 
     winContext = XUniqueContext();
diff --git a/dlls/winex11.drv/x11drv.h b/dlls/winex11.drv/x11drv.h
index 860ba22eae4..995df13e843 100644
--- a/dlls/winex11.drv/x11drv.h
+++ b/dlls/winex11.drv/x11drv.h
@@ -394,6 +394,9 @@ struct x11drv_thread_data
     unsigned long warp_serial;     /* serial number of last pointer warp request */
     Window   clip_window;          /* window used for cursor clipping */
     BOOL     clipping_cursor;      /* whether thread is currently clipping the cursor */
+    Atom    *net_supported;        /* list of _NET_SUPPORTED atoms */
+    int      net_supported_count;  /* number of _NET_SUPPORTED atoms */
+    UINT     net_wm_state_mask;    /* mask of supported _NET_WM_STATE *bits */
 #ifdef HAVE_X11_EXTENSIONS_XINPUT2_H
     XIValuatorClassInfo x_valuator;
     XIValuatorClassInfo y_valuator;
@@ -663,6 +666,8 @@ extern void window_net_wm_state_notify( struct x11drv_win_data *data, unsigned l
 extern void window_configure_notify( struct x11drv_win_data *data, unsigned long serial, const RECT *rect );
 extern BOOL get_window_state_updates( HWND hwnd, UINT *state_cmd, UINT *config_cmd, RECT *rect );
 
+extern void net_supported_init( struct x11drv_thread_data *data );
+
 extern Window init_clip_window(void);
 extern void update_user_time( Time time );
 extern UINT get_window_net_wm_state( Display *display, Window window );
diff --git a/dlls/winex11.drv/x11drv_main.c b/dlls/winex11.drv/x11drv_main.c
index e441298c9aa..30c5e35cfed 100644
--- a/dlls/winex11.drv/x11drv_main.c
+++ b/dlls/winex11.drv/x11drv_main.c
@@ -689,6 +689,7 @@ void X11DRV_ThreadDetach(void)
     {
         if (data->xim) XCloseIM( data->xim );
         if (data->font_set) XFreeFontSet( data->display, data->font_set );
+        if (data->net_supported) XFree( data->net_supported );
         XSync( gdi_display, False ); /* make sure XReparentWindow requests have completed before closing the thread display */
         XCloseDisplay( data->display );
         free( data );
@@ -755,6 +756,7 @@ struct x11drv_thread_data *x11drv_init_thread_data(void)
 
     if (use_xim) xim_thread_attach( data );
     x11drv_xinput2_init( data );
+    net_supported_init( data );
 
     return data;
 }
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/6944

[PATCH v3 2/5] winex11: Listen to root window _NET_SUPPORTED property changes.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

This might happen if the window manager is restarted or changed while a
Wine window is opened. We should support that use case properly.
---
 dlls/winex11.drv/event.c       | 17 +++++++++++++++++
 dlls/winex11.drv/window.c      |  2 +-
 dlls/winex11.drv/x11drv_main.c |  1 +
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/dlls/winex11.drv/event.c b/dlls/winex11.drv/event.c
index 65b31518691..cf9fd96a2fb 100644
--- a/dlls/winex11.drv/event.c
+++ b/dlls/winex11.drv/event.c
@@ -1245,6 +1245,21 @@ static void handle_net_wm_state_notify( HWND hwnd, XPropertyEvent *event )
     NtUserPostMessage( hwnd, WM_WINE_WINDOW_STATE_CHANGED, 0, 0 );
 }
 
+static void handle_net_supported_notify( XPropertyEvent *event )
+{
+    struct x11drv_thread_data *data = x11drv_thread_data();
+
+    if (data->net_supported)
+    {
+        data->net_supported_count = 0;
+        XFree( data->net_supported );
+        data->net_supported = NULL;
+        data->net_wm_state_mask = 0;
+    }
+
+    if (event->state == PropertyNewValue) net_supported_init( data );
+}
+
 /***********************************************************************
  *           X11DRV_PropertyNotify
  */
@@ -1256,6 +1271,8 @@ static BOOL X11DRV_PropertyNotify( HWND hwnd, XEvent *xev )
     if (event->atom == x11drv_atom(WM_STATE)) handle_wm_state_notify( hwnd, event );
     if (event->atom == x11drv_atom(_XEMBED_INFO)) handle_xembed_info_notify( hwnd, event );
     if (event->atom == x11drv_atom(_NET_WM_STATE)) handle_net_wm_state_notify( hwnd, event );
+    if (event->atom == x11drv_atom(_NET_SUPPORTED)) handle_net_supported_notify( event );
+
     return TRUE;
 }
 
diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index e35a3ff1873..179ca0b5ca3 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -2536,7 +2536,7 @@ void X11DRV_SystrayDockInit( HWND hwnd )
         sprintf( systray_buffer, "_NET_SYSTEM_TRAY_S%u", DefaultScreen( display ) );
         systray_atom = XInternAtom( display, systray_buffer, False );
     }
-    XSelectInput( display, root_window, StructureNotifyMask );
+    XSelectInput( display, root_window, StructureNotifyMask | PropertyChangeMask );
 }
 
 
diff --git a/dlls/winex11.drv/x11drv_main.c b/dlls/winex11.drv/x11drv_main.c
index 30c5e35cfed..a9ef67085f1 100644
--- a/dlls/winex11.drv/x11drv_main.c
+++ b/dlls/winex11.drv/x11drv_main.c
@@ -754,6 +754,7 @@ struct x11drv_thread_data *x11drv_init_thread_data(void)
     set_queue_display_fd( data->display );
     NtUserGetThreadInfo()->driver_data = (UINT_PTR)data;
 
+    XSelectInput( data->display, DefaultRootWindow( data->display ), PropertyChangeMask );
     if (use_xim) xim_thread_attach( data );
     x11drv_xinput2_init( data );
     net_supported_init( data );
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/6944

[PATCH v3 3/5] winex11: Keep track of the _NET_SUPPORTING_WM_CHECK window.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

---
 dlls/winex11.drv/event.c       |  8 ++++++++
 dlls/winex11.drv/window.c      | 28 ++++++++++++++++++++++++++++
 dlls/winex11.drv/x11drv.h      |  2 ++
 dlls/winex11.drv/x11drv_main.c |  2 ++
 4 files changed, 40 insertions(+)

diff --git a/dlls/winex11.drv/event.c b/dlls/winex11.drv/event.c
index cf9fd96a2fb..e20d5cb70b5 100644
--- a/dlls/winex11.drv/event.c
+++ b/dlls/winex11.drv/event.c
@@ -1260,6 +1260,13 @@ static void handle_net_supported_notify( XPropertyEvent *event )
     if (event->state == PropertyNewValue) net_supported_init( data );
 }
 
+static void handle_net_supporting_wm_check_notify( XPropertyEvent *event )
+{
+    struct x11drv_thread_data *data = x11drv_thread_data();
+
+    if (event->state == PropertyNewValue) net_supporting_wm_check_init( data );
+}
+
 /***********************************************************************
  *           X11DRV_PropertyNotify
  */
@@ -1272,6 +1279,7 @@ static BOOL X11DRV_PropertyNotify( HWND hwnd, XEvent *xev )
     if (event->atom == x11drv_atom(_XEMBED_INFO)) handle_xembed_info_notify( hwnd, event );
     if (event->atom == x11drv_atom(_NET_WM_STATE)) handle_net_wm_state_notify( hwnd, event );
     if (event->atom == x11drv_atom(_NET_SUPPORTED)) handle_net_supported_notify( event );
+    if (event->atom == x11drv_atom(_NET_SUPPORTING_WM_CHECK)) handle_net_supporting_wm_check_notify( event );
 
     return TRUE;
 }
diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index 179ca0b5ca3..d31f0d87030 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -3417,6 +3417,34 @@ void net_supported_init( struct x11drv_thread_data *data )
     }
 }
 
+static Window get_net_supporting_wm_check( Display *display, Window window )
+{
+    unsigned long count, remaining;
+    Window *tmp, support = None;
+    int format;
+    Atom type;
+
+    if (!XGetWindowProperty( display, window, x11drv_atom(_NET_SUPPORTING_WM_CHECK), 0, 65536 / sizeof(CARD32),
+                             False, XA_WINDOW, &type, &format, &count, &remaining, (unsigned char **)&tmp ))
+    {
+        support = *tmp;
+        free( tmp );
+    }
+
+    return support;
+}
+
+void net_supporting_wm_check_init( struct x11drv_thread_data *data )
+{
+    Window window = None, other;
+
+    window = get_net_supporting_wm_check( data->display, DefaultRootWindow( data->display ) );
+    /* the window itself must have the property set too */
+    X11DRV_expect_error( data->display, host_window_error, NULL );
+    other = get_net_supporting_wm_check( data->display, window );
+    if (X11DRV_check_error() || window != other) WARN( "Invalid _NET_SUPPORTING_WM_CHECK window\n" );
+}
+
 void init_win_context(void)
 {
     init_recursive_mutex( &win_data_mutex );
diff --git a/dlls/winex11.drv/x11drv.h b/dlls/winex11.drv/x11drv.h
index 995df13e843..324e9d0f3ae 100644
--- a/dlls/winex11.drv/x11drv.h
+++ b/dlls/winex11.drv/x11drv.h
@@ -487,6 +487,7 @@ enum x11drv_atoms
     XATOM__NET_STARTUP_INFO_BEGIN,
     XATOM__NET_STARTUP_INFO,
     XATOM__NET_SUPPORTED,
+    XATOM__NET_SUPPORTING_WM_CHECK,
     XATOM__NET_SYSTEM_TRAY_OPCODE,
     XATOM__NET_SYSTEM_TRAY_S0,
     XATOM__NET_SYSTEM_TRAY_VISUAL,
@@ -667,6 +668,7 @@ extern void window_configure_notify( struct x11drv_win_data *data, unsigned long
 extern BOOL get_window_state_updates( HWND hwnd, UINT *state_cmd, UINT *config_cmd, RECT *rect );
 
 extern void net_supported_init( struct x11drv_thread_data *data );
+extern void net_supporting_wm_check_init( struct x11drv_thread_data *data );
 
 extern Window init_clip_window(void);
 extern void update_user_time( Time time );
diff --git a/dlls/winex11.drv/x11drv_main.c b/dlls/winex11.drv/x11drv_main.c
index a9ef67085f1..99d2dbd8c97 100644
--- a/dlls/winex11.drv/x11drv_main.c
+++ b/dlls/winex11.drv/x11drv_main.c
@@ -132,6 +132,7 @@ static const char * const atom_names[NB_XATOMS - FIRST_XATOM] =
     "_NET_STARTUP_INFO_BEGIN",
     "_NET_STARTUP_INFO",
     "_NET_SUPPORTED",
+    "_NET_SUPPORTING_WM_CHECK",
     "_NET_SYSTEM_TRAY_OPCODE",
     "_NET_SYSTEM_TRAY_S0",
     "_NET_SYSTEM_TRAY_VISUAL",
@@ -758,6 +759,7 @@ struct x11drv_thread_data *x11drv_init_thread_data(void)
     if (use_xim) xim_thread_attach( data );
     x11drv_xinput2_init( data );
     net_supported_init( data );
+    net_supporting_wm_check_init( data );
 
     return data;
 }
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/6944

[PATCH v3 4/5] winex11: Keep track of the window manager name.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

---
 dlls/winex11.drv/event.c       |  6 ++++++
 dlls/winex11.drv/window.c      | 15 +++++++++++++++
 dlls/winex11.drv/x11drv.h      |  2 ++
 dlls/winex11.drv/x11drv_main.c |  2 ++
 4 files changed, 25 insertions(+)

diff --git a/dlls/winex11.drv/event.c b/dlls/winex11.drv/event.c
index e20d5cb70b5..29967539c20 100644
--- a/dlls/winex11.drv/event.c
+++ b/dlls/winex11.drv/event.c
@@ -1264,6 +1264,12 @@ static void handle_net_supporting_wm_check_notify( XPropertyEvent *event )
 {
     struct x11drv_thread_data *data = x11drv_thread_data();
 
+    if (data->window_manager)
+    {
+        XFree( data->window_manager );
+        data->window_manager = NULL;
+    }
+
     if (event->state == PropertyNewValue) net_supporting_wm_check_init( data );
 }
 
diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index d31f0d87030..b2684f7dfd2 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -3434,6 +3434,18 @@ static Window get_net_supporting_wm_check( Display *display, Window window )
     return support;
 }
 
+static BOOL get_window_property_str( Display *display, Window window, Atom atom, char **name )
+{
+    unsigned long count, remaining;
+    int format, ret;
+    Atom type;
+
+    X11DRV_expect_error( display, host_window_error, NULL );
+    ret = XGetWindowProperty( display, window, atom, 0, 65536 / sizeof(CARD32), False, x11drv_atom(UTF8_STRING),
+                              &type, &format, &count, &remaining, (unsigned char **)name );
+    return !X11DRV_check_error() && !ret;
+}
+
 void net_supporting_wm_check_init( struct x11drv_thread_data *data )
 {
     Window window = None, other;
@@ -3443,6 +3455,9 @@ void net_supporting_wm_check_init( struct x11drv_thread_data *data )
     X11DRV_expect_error( data->display, host_window_error, NULL );
     other = get_net_supporting_wm_check( data->display, window );
     if (X11DRV_check_error() || window != other) WARN( "Invalid _NET_SUPPORTING_WM_CHECK window\n" );
+    else if (get_window_property_str( data->display, window, x11drv_atom(_NET_WM_NAME), &data->window_manager ) ||
+             get_window_property_str( data->display, window, x11drv_atom(WM_NAME), &data->window_manager ))
+        TRACE( "Detected window manager: %s\n", debugstr_a(data->window_manager) );
 }
 
 void init_win_context(void)
diff --git a/dlls/winex11.drv/x11drv.h b/dlls/winex11.drv/x11drv.h
index 324e9d0f3ae..ed72214bf58 100644
--- a/dlls/winex11.drv/x11drv.h
+++ b/dlls/winex11.drv/x11drv.h
@@ -397,6 +397,7 @@ struct x11drv_thread_data
     Atom    *net_supported;        /* list of _NET_SUPPORTED atoms */
     int      net_supported_count;  /* number of _NET_SUPPORTED atoms */
     UINT     net_wm_state_mask;    /* mask of supported _NET_WM_STATE *bits */
+    char    *window_manager;       /* name of the supporting window manager */
 #ifdef HAVE_X11_EXTENSIONS_XINPUT2_H
     XIValuatorClassInfo x_valuator;
     XIValuatorClassInfo y_valuator;
@@ -477,6 +478,7 @@ enum x11drv_atoms
     XATOM_RAW_CAP_HEIGHT,
     XATOM_WM_PROTOCOLS,
     XATOM_WM_DELETE_WINDOW,
+    XATOM_WM_NAME,
     XATOM_WM_STATE,
     XATOM_WM_TAKE_FOCUS,
     XATOM_DndProtocol,
diff --git a/dlls/winex11.drv/x11drv_main.c b/dlls/winex11.drv/x11drv_main.c
index 99d2dbd8c97..a939ed8cd92 100644
--- a/dlls/winex11.drv/x11drv_main.c
+++ b/dlls/winex11.drv/x11drv_main.c
@@ -122,6 +122,7 @@ static const char * const atom_names[NB_XATOMS - FIRST_XATOM] =
     "RAW_CAP_HEIGHT",
     "WM_PROTOCOLS",
     "WM_DELETE_WINDOW",
+    "WM_NAME",
     "WM_STATE",
     "WM_TAKE_FOCUS",
     "DndProtocol",
@@ -691,6 +692,7 @@ void X11DRV_ThreadDetach(void)
         if (data->xim) XCloseIM( data->xim );
         if (data->font_set) XFreeFontSet( data->display, data->font_set );
         if (data->net_supported) XFree( data->net_supported );
+        if (data->window_manager) XFree( data->window_manager );
         XSync( gdi_display, False ); /* make sure XReparentWindow requests have completed before closing the thread display */
         XCloseDisplay( data->display );
         free( data );
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/6944

[PATCH v3 5/5] winex11: Workaround KWin bug with maximized windows.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

---
 dlls/winex11.drv/window.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index b2684f7dfd2..50d1681c6c2 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -1278,7 +1278,8 @@ static void window_set_net_wm_state( struct x11drv_win_data *data, UINT new_stat
 static void window_set_config( struct x11drv_win_data *data, const RECT *new_rect, BOOL above )
 {
     static const UINT fullscreen_mask = (1 << NET_WM_STATE_MAXIMIZED) | (1 << NET_WM_STATE_FULLSCREEN);
-    UINT style = NtUserGetWindowLongW( data->hwnd, GWL_STYLE ), mask = 0;
+    UINT style = NtUserGetWindowLongW( data->hwnd, GWL_STYLE ), mask = 0, net_wm_state = -1;
+    struct x11drv_thread_data *thread_data = x11drv_thread_data();
     const RECT *old_rect = &data->pending_state.rect;
     XWindowChanges changes;
 
@@ -1286,16 +1287,25 @@ static void window_set_config( struct x11drv_win_data *data, const RECT *new_rec
     if (!data->whole_window) return; /* no window, nothing to update */
     if (EqualRect( old_rect, new_rect )) return; /* rects are the same, nothing to update */
 
-    if (data->pending_state.wm_state == NormalState && data->net_wm_state_serial &&
-        !(data->pending_state.net_wm_state & fullscreen_mask) &&
-        (data->current_state.net_wm_state & fullscreen_mask))
+    if (((data->pending_state.net_wm_state | data->current_state.net_wm_state) & fullscreen_mask) &&
+        data->pending_state.wm_state == NormalState)
     {
         /* Some window managers are sending a ConfigureNotify event with the fullscreen size when
          * exiting a fullscreen window, with a serial that we cannot predict. Handling that event
          * will override the Win32 window size and make the window fullscreen again.
          */
-        WARN( "window %p/%lx is exiting maximize/fullscreen, delaying request\n", data->hwnd, data->whole_window );
-        return;
+        if (data->net_wm_state_serial)
+        {
+            WARN( "window %p/%lx is updating _NET_WM_STATE, delaying request\n", data->hwnd, data->whole_window );
+            return;
+        }
+
+        if (thread_data->window_manager && !strcmp( thread_data->window_manager, "KWin" ))
+        {
+            /* Workaround for KWin bug 496966: clear maximized state before requesting new config */
+            net_wm_state = data->pending_state.net_wm_state;
+            window_set_net_wm_state( data, net_wm_state & ~fullscreen_mask );
+        }
     }
 
     /* resizing a managed maximized window is not allowed */
@@ -1330,6 +1340,9 @@ static void window_set_config( struct x11drv_win_data *data, const RECT *new_rec
     TRACE( "window %p/%lx, requesting config %s above %u, serial %lu\n", data->hwnd, data->whole_window,
            wine_dbgstr_rect(new_rect), above, data->configure_serial );
     XReconfigureWMWindow( data->display, data->whole_window, data->vis.screen, mask, &changes );
+
+    /* Workaround for KWin bug 496966: restore maximized state after requesting new config */
+    if (net_wm_state != -1) window_set_net_wm_state( data, net_wm_state );
 }
 
 /***********************************************************************
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/6944

[Rémi Bernon]

Fwiw the KWin fix has been merged and planned for 6.3, although I don't expect it to be backported to all older KWin versions.

Also, another use-case for having WM detection, is that the display mode emulation is truly only useful on X server with a window manager that is not Gamescope. Under Xwayland (which could be detected in a similar way), or Gamescope, the feature is not really useful and maybe even not desirable.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6944#note_89811

[Aida Jonikienė]

The first 2 commits are merged now (so you should remove these in the next rebase)

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6944#note_90097