[PATCH v4 4/6] win32u: Lock display devices while applying display settings.

[Rémi Bernon]

From: Rémi Bernon

---
 dlls/win32u/sysparams.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index b7ab0a6880d..4be1e0b9a3b 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -2252,10 +2252,8 @@ static DEVMODEW *get_display_settings( const WCHAR *devname, const DEVMODEW *dev
     struct adapter *adapter;
     BOOL ret;

-    if (!lock_display_devices()) return NULL;
-
     /* allocate an extra mode for easier iteration */
-    if (!(displays = calloc( list_count( &adapters ) + 1, sizeof(DEVMODEW) ))) goto done;
+    if (!(displays = calloc( list_count( &adapters ) + 1, sizeof(DEVMODEW) ))) return NULL;
     mode = displays;

LIST_FOR_EACH_ENTRY( adapter, &adapters, struct adapter, entry )
@@ -2267,20 +2265,18 @@ static DEVMODEW *get_display_settings( const WCHAR *devname, const DEVMODEW *dev
         {
             if (!devname) ret = adapter_get_registry_settings( adapter, mode );
             else ret = user_driver->pGetCurrentDisplaySettings( adapter->dev.device_name, mode );
-            if (!ret) goto done;
+            if (!ret)
+            {
+                free( displays );
+                return NULL;
+            }
         }

lstrcpyW( mode->dmDeviceName, adapter->dev.device_name );
         mode = NEXT_DEVMODEW(mode);
     }

-    unlock_display_devices();
     return displays;
-
-done:
-    unlock_display_devices();
-    free( displays );
-    return NULL;
 }

static INT offset_length( POINT offset )
@@ -2477,11 +2473,16 @@ static LONG apply_display_settings( const WCHAR *devname, const DEVMODEW *devmod
     DEVMODEW *displays;
     LONG ret;

-    displays = get_display_settings( devname, devmode );
-    if (!displays) return DISP_CHANGE_FAILED;
+    if (!lock_display_devices()) return DISP_CHANGE_FAILED;
+    if (!(displays = get_display_settings( devname, devmode )))
+    {
+        unlock_display_devices();
+        return DISP_CHANGE_FAILED;
+    }

if (all_detached_settings( displays ))
     {
+        unlock_display_devices();
         WARN( "Detaching all modes is not permitted.\n" );
         free( displays );
         return DISP_CHANGE_SUCCESSFUL;
@@ -2490,7 +2491,7 @@ static LONG apply_display_settings( const WCHAR *devname, const DEVMODEW *devmod
     place_all_displays( displays );

ret = user_driver->pChangeDisplaySettings( displays, hwnd, flags, lparam );
-
+    unlock_display_devices();
     free( displays );
     if (ret) return ret;