Clear an old button text in WM_SETTEXT as Windows does

[Dmitry Timoshkov <dmitry@baikal.ru>]

Hello.

This is a fix for WineHQ bug #437.

P.S.
Could somebody with slightly more free time fix DrawText(DT_CALCRECT),
since it returns width much larger than an expected value?
To test just replace
hbrush = SendMessageW(GetParent(hWnd), WM_CTLCOLORSTATIC, hdc, (LPARAM)hWnd);
by
hbrush = GetStockObject(WHITE_BRUSH);
below.

Thanks in advance.

Changelog:
    Dmitry Timoshkov <dmitry@codeweavers.com>
    Clear an old button text in WM_SETTEXT as Windows does.

--- cvs/hq/wine/controls/button.c	Tue Mar 12 13:38:27 2002
+++ wine/controls/button.c	Mon May 20 22:03:06 2002
@@ -47,6 +47,7 @@
 #define BUTTON_UNKNOWN2        0x20
 #define BUTTON_UNKNOWN3        0x10
 
+static UINT BUTTON_CalcLabelRect( HWND hwnd, HDC hdc, RECT *rc );
 static void PB_Paint( HWND hwnd, HDC hDC, UINT action );
 static void CB_Paint( HWND hwnd, HDC hDC, UINT action );
 static void GB_Paint( HWND hwnd, HDC hDC, UINT action );
@@ -301,10 +302,33 @@
         break;
 
     case WM_SETTEXT:
+    {
+        /* Clear an old text here as Windows does */
+        HDC hdc = GetDC(hWnd);
+        HBRUSH hbrush;
+        RECT client, rc;
+
+        hbrush = SendMessageW(GetParent(hWnd), WM_CTLCOLORSTATIC, hdc, (LPARAM)hWnd);
+        if (!hbrush) /* did the app forget to call DefWindowProc ? */
+            hbrush = DefWindowProcW(GetParent(hWnd), WM_CTLCOLORSTATIC, hdc, (LPARAM)hWnd);
+
+        GetClientRect(hWnd, &client);
+        rc = client;
+        BUTTON_CalcLabelRect(hWnd, hdc, &rc);
+        /* Clip by client rect bounds */
+        if (rc.right > client.right) rc.right = client.right;
+        if (rc.bottom > client.bottom) rc.bottom = client.bottom;
+        FillRect(hdc, &rc, hbrush);
+        ReleaseDC(hWnd, hdc);
+
         if (unicode) DefWindowProcW( hWnd, WM_SETTEXT, wParam, lParam );
         else DefWindowProcA( hWnd, WM_SETTEXT, wParam, lParam );
-        paint_button( hWnd, btn_type, ODA_DRAWENTIRE );
+        if (btn_type == BS_GROUPBOX) /* Yes, only for BS_GROUPBOX */
+            InvalidateRect( hWnd, NULL, TRUE );
+        else
+            paint_button( hWnd, btn_type, ODA_DRAWENTIRE );
         return 1; /* success. FIXME: check text length */
+    }
 
     case WM_SETFONT:
         set_button_font( hWnd, wParam );