user32/tests: Add basic tests for GetUserObjectSecurity().

dlls/user32/tests/winstation.c

@@ -1093,6 +1093,31 @@ static void test_invisible_winstation(char **argv)
     SetProcessWindowStation(old_winstation);
 }
 
+static void test_get_security(void)
+{
+    SECURITY_INFORMATION info = DACL_SECURITY_INFORMATION;
+    HDESK desktop = GetThreadDesktop(GetCurrentThreadId());
+    DWORD size, expect_size;
+    char buffer[500];
+    BOOL ret;
+
+    size = 0xdeadbeef;
+    SetLastError(0xdeadbeef);
+    ret = GetUserObjectSecurity( desktop, &info, NULL, 0, &size );
+    ok( !ret, "got %#x\n", ret );
+    ok( GetLastError() == ERROR_INSUFFICIENT_BUFFER, "got error %lu\n", GetLastError() );
+    ok( size && size < sizeof(buffer), "got size %lu\n", size );
+    expect_size = size;
+
+    size = 0xdeadbeef;
+    SetLastError(0xdeadbeef);
+    ret = GetUserObjectSecurity( desktop, &info, buffer, sizeof(buffer), &size );
+    ok( ret == TRUE, "got %#x\n", ret );
+    ok( GetLastError() == 0xdeadbeef, "got error %lu\n", GetLastError() );
+    ok( size == expect_size, "got size %lu\n", size );
+    ok( IsValidSecurityDescriptor(buffer), "expected valid SD\n" );
+}
+
 START_TEST(winstation)
 {
     char **argv;
@@ -1126,4 +1151,5 @@ START_TEST(winstation)
     test_getuserobjectinformation();
     test_foregroundwindow();
     test_invisible_winstation(argv);
+    test_get_security();
 }