From 8a4ec0addba76bf3b34a9782556364ab4161dc22 Mon Sep 17 00:00:00 2001
From: Zhiyi Zhang <zzhang@codeweavers.com>
Date: Tue, 26 May 2020 16:35:09 +0800
Subject: [PATCH] user32: Handle NULL device and mode parameters in
 ChangeDisplaySettingsExW().

NULL device and mode parameters mean to restore all adapters to their
registry settings. Since all user graphics drivers only support a
primary adapter now, it's okay to restore only the primary adapter.

Signed-off-by: Zhiyi Zhang <zzhang@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
---
 dlls/user32/sysparams.c     |  3 +++
 dlls/winemac.drv/display.c  | 35 +++++++++++++++++++++++++++++++++++
 dlls/winex11.drv/settings.c | 36 ++++++++++++++++++++++++++++++++++++
 dlls/winex11.drv/x11drv.h   |  1 +
 4 files changed, 75 insertions(+)

diff --git a/dlls/user32/sysparams.c b/dlls/user32/sysparams.c
index 10f17bb4c3e..e6f33006dbf 100644
--- a/dlls/user32/sysparams.c
+++ b/dlls/user32/sysparams.c
@@ -3300,6 +3300,9 @@ LONG WINAPI ChangeDisplaySettingsExW( LPCWSTR devname, LPDEVMODEW devmode, HWND
     TRACE("%s %p %p %#x %p\n", debugstr_w(devname), devmode, hwnd, flags, lparam);
     TRACE("flags=%s\n", _CDS_flags(flags));
 
+    if (!devname && !devmode)
+        return USER_Driver->pChangeDisplaySettingsEx(NULL, NULL, hwnd, flags, lparam);
+
     if (!devname && devmode)
     {
         if (!get_primary_adapter(primary_adapter))
diff --git a/dlls/winemac.drv/display.c b/dlls/winemac.drv/display.c
index 851d549d5fa..968b9277bba 100644
--- a/dlls/winemac.drv/display.c
+++ b/dlls/winemac.drv/display.c
@@ -747,6 +747,23 @@ void check_retina_status(void)
     }
 }
 
+static BOOL get_primary_adapter(WCHAR *name)
+{
+    DISPLAY_DEVICEW dd;
+    DWORD i;
+
+    dd.cb = sizeof(dd);
+    for (i = 0; EnumDisplayDevicesW(NULL, i, &dd, 0); ++i)
+    {
+        if (dd.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE)
+        {
+            lstrcpyW(name, dd.DeviceName);
+            return TRUE;
+        }
+    }
+
+    return FALSE;
+}
 
 /***********************************************************************
  *              ChangeDisplaySettingsEx  (MACDRV.@)
@@ -755,7 +772,9 @@ void check_retina_status(void)
 LONG CDECL macdrv_ChangeDisplaySettingsEx(LPCWSTR devname, LPDEVMODEW devmode,
                                           HWND hwnd, DWORD flags, LPVOID lpvoid)
 {
+    WCHAR primary_adapter[CCHDEVICENAME];
     LONG ret = DISP_CHANGE_BADMODE;
+    DEVMODEW default_mode;
     int bpp;
     struct macdrv_display *displays;
     int num_displays;
@@ -770,6 +789,22 @@ LONG CDECL macdrv_ChangeDisplaySettingsEx(LPCWSTR devname, LPDEVMODEW devmode,
 
     init_original_display_mode();
 
+    if (!get_primary_adapter(primary_adapter))
+        return DISP_CHANGE_FAILED;
+
+    if (!devname && !devmode)
+    {
+        default_mode.dmSize = sizeof(default_mode);
+        if (!EnumDisplaySettingsExW(primary_adapter, ENUM_REGISTRY_SETTINGS, &default_mode, 0))
+        {
+            ERR("Default mode not found for %s!\n", wine_dbgstr_w(primary_adapter));
+            return DISP_CHANGE_BADMODE;
+        }
+
+        devname = primary_adapter;
+        devmode = &default_mode;
+    }
+
     if (macdrv_get_displays(&displays, &num_displays))
         return DISP_CHANGE_FAILED;
 
diff --git a/dlls/winex11.drv/settings.c b/dlls/winex11.drv/settings.c
index 24644db6203..3e7a5960f02 100644
--- a/dlls/winex11.drv/settings.c
+++ b/dlls/winex11.drv/settings.c
@@ -252,6 +252,24 @@ static BOOL write_registry_settings(const DEVMODEW *dm)
     return ret;
 }
 
+BOOL get_primary_adapter(WCHAR *name)
+{
+    DISPLAY_DEVICEW dd;
+    DWORD i;
+
+    dd.cb = sizeof(dd);
+    for (i = 0; EnumDisplayDevicesW(NULL, i, &dd, 0); ++i)
+    {
+        if (dd.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE)
+        {
+            lstrcpyW(name, dd.DeviceName);
+            return TRUE;
+        }
+    }
+
+    return FALSE;
+}
+
 /***********************************************************************
  *		EnumDisplaySettingsEx  (X11DRV.@)
  *
@@ -318,9 +336,27 @@ BOOL CDECL X11DRV_EnumDisplaySettingsEx( LPCWSTR name, DWORD n, LPDEVMODEW devmo
 LONG CDECL X11DRV_ChangeDisplaySettingsEx( LPCWSTR devname, LPDEVMODEW devmode,
                                            HWND hwnd, DWORD flags, LPVOID lpvoid )
 {
+    WCHAR primary_adapter[CCHDEVICENAME];
     char bpp_buffer[16], freq_buffer[18];
+    DEVMODEW default_mode;
     DWORD i;
 
+    if (!get_primary_adapter(primary_adapter))
+        return DISP_CHANGE_FAILED;
+
+    if (!devname && !devmode)
+    {
+        default_mode.dmSize = sizeof(default_mode);
+        if (!EnumDisplaySettingsExW(primary_adapter, ENUM_REGISTRY_SETTINGS, &default_mode, 0))
+        {
+            ERR("Default mode not found for %s!\n", wine_dbgstr_w(primary_adapter));
+            return DISP_CHANGE_BADMODE;
+        }
+
+        devname = primary_adapter;
+        devmode = &default_mode;
+    }
+
     for (i = 0; i < dd_mode_count; i++)
     {
         if (devmode->dmFields & DM_BITSPERPEL)
diff --git a/dlls/winex11.drv/x11drv.h b/dlls/winex11.drv/x11drv.h
index ff0aeb7dab2..52057e875d5 100644
--- a/dlls/winex11.drv/x11drv.h
+++ b/dlls/winex11.drv/x11drv.h
@@ -661,6 +661,7 @@ extern void X11DRV_resize_desktop(BOOL) DECLSPEC_HIDDEN;
 extern BOOL is_virtual_desktop(void) DECLSPEC_HIDDEN;
 extern BOOL is_desktop_fullscreen(void) DECLSPEC_HIDDEN;
 extern BOOL create_desktop_win_data( Window win ) DECLSPEC_HIDDEN;
+extern BOOL get_primary_adapter(WCHAR *) DECLSPEC_HIDDEN;
 extern void X11DRV_Settings_AddDepthModes(void) DECLSPEC_HIDDEN;
 extern void X11DRV_Settings_AddOneMode(unsigned int width, unsigned int height, unsigned int bpp, unsigned int freq) DECLSPEC_HIDDEN;
 unsigned int X11DRV_Settings_GetModeCount(void) DECLSPEC_HIDDEN;