[PATCH v4 3/8] win32u: Return the current display mode depth with nulldrv.

[Rémi Bernon]

From: Rémi Bernon

---
 dlls/win32u/driver.c    |  2 +-
 dlls/win32u/sysparams.c | 13 +++++++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/dlls/win32u/driver.c b/dlls/win32u/driver.c
index 1c0708461a1..3f676dc5796 100644
--- a/dlls/win32u/driver.c
+++ b/dlls/win32u/driver.c
@@ -761,7 +761,7 @@ static BOOL nulldrv_GetCurrentDisplaySettings( LPCWSTR name, BOOL is_primary, LP

static INT nulldrv_GetDisplayDepth( LPCWSTR name, BOOL is_primary )
 {
-    return 32;
+    return -1; /* use default implementation */
 }

static BOOL nulldrv_UpdateDisplayDevices( const struct gdi_device_manager *manager, BOOL force, void *param )
diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index bcdb8c5103b..60b12321953 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -2727,6 +2727,7 @@ static unsigned int active_monitor_count(void)
 INT get_display_depth( UNICODE_STRING *name )
 {
     struct display_device *device;
+    BOOL is_primary;
     INT depth;

if (!lock_display_devices())
@@ -2743,8 +2744,16 @@ INT get_display_depth( UNICODE_STRING *name )
         return 32;
     }

-    depth = user_driver->pGetDisplayDepth( device->device_name,
-                                           !!(device->state_flags & DISPLAY_DEVICE_PRIMARY_DEVICE) );
+    is_primary = !!(device->state_flags & DISPLAY_DEVICE_PRIMARY_DEVICE);
+    if ((depth = user_driver->pGetDisplayDepth( device->device_name, is_primary )) < 0)
+    {
+        struct adapter *adapter = CONTAINING_RECORD( device, struct adapter, dev );
+        DEVMODEW current_mode = {.dmSize = sizeof(DEVMODEW)};
+
+        if (!adapter_get_current_settings( adapter, &current_mode )) depth = 32;
+        else depth = current_mode.dmBitsPerPel;
+    }
+
     unlock_display_devices();
     return depth;
 }