[USER32]

- Delete region on error path.
[WIN32SS]
 - Improve/add a few debug prints.

svn path=/trunk/; revision=64182

reactos/win32ss/user/ntuser/windc.c

@@ -1037,7 +1037,8 @@ NtUserGetDCEx(HWND hWnd OPTIONAL, HANDLE ClipRegion, ULONG Flags)
   PWND Wnd=NULL;
   DECLARE_RETURN(HDC);
 
-  TRACE("Enter NtUserGetDCEx\n");
+  TRACE("Enter NtUserGetDCEx: hWnd %p, ClipRegion %p, Flags %x.\n",
+      hWnd, ClipRegion, Flags);
   UserEnterExclusive();
 
   if (hWnd && !(Wnd = UserGetWindowObject(hWnd)))

reactos/win32ss/user/user32/windows/message.c

@@ -1619,6 +1619,9 @@ IntCallWindowProcA(BOOL IsAnsiProc,
   LRESULT Result = 0, PreResult = 0;
   DWORD Data = 0;
 
+  TRACE("IntCallWindowProcA: IsAnsiProc : %s, WndProc %p, pWnd %p, hWnd %p, Msg %u, wParam %Iu, lParam %Iu.\n",
+      IsAnsiProc ? "TRUE" : "FALSE", WndProc, pWnd, hWnd, Msg, wParam, lParam);
+
   if (WndProc == NULL)
   {
       WARN("IntCallWindowsProcA() called with WndProc = NULL!\n");

reactos/win32ss/user/user32/windows/nonclient.c

@@ -281,9 +281,15 @@ DefWndNCPaint(HWND hWnd, HRGN hRgn, BOOL Active)
 
    Style = GetWindowLongPtrW(hWnd, GWL_STYLE);
 
+   TRACE("DefWndNCPaint: hWnd %p, hRgn %p, Active %s.\n",
+       hWnd, hRgn, Active ? "TRUE" : "FALSE");
+
    hDC = GetDCEx(hWnd, hRgn, DCX_WINDOW | DCX_INTERSECTRGN | DCX_USESTYLE | DCX_KEEPCLIPRGN);
    if (hDC == 0)
    {
+      ERR("hDC is NULL!\n");
+      if (hRgn != HRGN_WINDOW)
+          DeleteObject(hRgn);
       return 0;
    }