[PATCH] user16: Fix truncation for 16-bit handles.

[Oleh Nykyforchyn]

When background is erased in a 16 bit app, a handle to DC is passed
through USER16 functions, namely CallWindowProc16 (USER.122) and
DefDriverProc16 (USER.255), whose respective parameters are of type
WPARAM16, hence the upper part of the handle is truncated. Later
the returned handle is rejected by get_dc_attr() in GDI32 because
its type is 0, although such handles are accepted by handle_entry().
This results in black and not cleared background.  If handles are
restored with HDC_32(), they pass get_dc_attr() successfully.

Based on a patch by Nikolay Sivov.

Supercedes https://source.winehq.org/patches/data/218030

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=51899
Signed-off-by: Oleh Nykyforchyn <oleh.nyk(a)gmail.com>
---
 dlls/user.exe16/message.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/dlls/user.exe16/message.c b/dlls/user.exe16/message.c
index 93e2cc018bf..eb1d957847a 100644
--- a/dlls/user.exe16/message.c
+++ b/dlls/user.exe16/message.c
@@ -899,6 +899,9 @@ LRESULT WINPROC_CallProc16To32A( winproc_callback_t callback, HWND16 hwnd, UINT1
     case WM_SIZECLIPBOARD:
         FIXME_(msg)( "message %04x needs translation\n", msg );
         break;
+    case WM_ERASEBKGND:
+        ret = callback( hwnd32, msg, (WPARAM)HDC_32(wParam), lParam, result, arg );
+        break;
     default:
         ret = callback( hwnd32, msg, wParam, lParam, result, arg );
         break;
@@ -1670,6 +1673,14 @@ LRESULT WINAPI DefWindowProc16( HWND16 hwnd16, UINT16 msg, WPARAM16 wParam, LPAR
     case WM_GETTEXT:
     case WM_SETTEXT:
         return DefWindowProcA( hwnd, msg, wParam, (LPARAM)MapSL(lParam) );
+    case WM_CTLCOLOR:
+        if (HIWORD(lParam) <= CTLCOLOR_STATIC)
+            return DefWindowProcA( hwnd, WM_CTLCOLORMSGBOX + HIWORD(lParam),
+                            (WPARAM)HDC_32(wParam), (LPARAM)WIN_Handle32( LOWORD(lParam) ) );
+        else
+            return 0;
+    case WM_ERASEBKGND:
+        return DefWindowProcA( hwnd, msg, (WPARAM)HDC_32(wParam), lParam );
     default:
         return DefWindowProcA( hwnd, msg, wParam, lParam );
     }
-- 
2.33.0