Zhiyi Zhang : user32: Handle NULL device and not NULL mode parameters in ChangeDisplaySettingsExW().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: ae157bec34a132d34ed04005f02f9fdf4845af97
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=ae157bec34a132d34ed04005f...

Author: Zhiyi Zhang 
Date:   Tue Feb 11 16:08:59 2020 +0800

user32: Handle NULL device and not NULL mode parameters in ChangeDisplaySettingsExW().

This makes sure that user graphics drivers has a valid device name when a
DEVMODE is specified.

Signed-off-by: Zhiyi Zhang 
Signed-off-by: Alexandre Julliard

---

dlls/user32/sysparams.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/dlls/user32/sysparams.c b/dlls/user32/sysparams.c
index e3919ad1b1..c5c98a7ea1 100644
--- a/dlls/user32/sysparams.c
+++ b/dlls/user32/sysparams.c
@@ -3293,12 +3293,21 @@ static void trace_devmode(const DEVMODEW *devmode)
 LONG WINAPI ChangeDisplaySettingsExW( LPCWSTR devname, LPDEVMODEW devmode, HWND hwnd,
                                       DWORD flags, LPVOID lparam )
 {
+    WCHAR primary_adapter[CCHDEVICENAME];
     BOOL def_mode = TRUE;
     DEVMODEW dm;

TRACE("%s %p %p %#x %p\n", debugstr_w(devname), devmode, hwnd, flags, lparam);
     TRACE("flags=%s\n", _CDS_flags(flags));

+    if (!devname && devmode)
+    {
+        if (!get_primary_adapter(primary_adapter))
+            return DISP_CHANGE_FAILED;
+
+        devname = primary_adapter;
+    }
+
     if (devmode)
     {
         trace_devmode(devmode);