[PATCH 0/1] MR869: win32u: Copy directly into the union pointer in unpack_message().

[Zebediah Figura (＠zfigura)]

This is a gcc bug; I've filed the following bug report:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106904

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/869

[PATCH 1/1] win32u: Copy directly into the union pointer in unpack_message().

[Zebediah Figura]

From: Zebediah Figura <zfigura(a)codeweavers.com>

This works around a spurious gcc warning:

../wine/dlls/win32u/message.c: In function ‘unpack_message.constprop’:
../wine/dlls/win32u/message.c:359:9: error: writing 28 bytes into a region of size 4 [-Werror=stringop-overflow=]
  359 |         memcpy( &ps->wp, &wp, sizeof(wp) );
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ../wine/dlls/win32u/win32u_private.h:29,
                 from ../wine/dlls/win32u/message.c:30:
../wine/include/ntuser.h:549:15: note: destination object ‘hwnd’ of size 4
  549 |     UINT      hwnd;
      |               ^~~~
---
 dlls/win32u/message.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c
index f4f134e213b..57e9b26b33d 100644
--- a/dlls/win32u/message.c
+++ b/dlls/win32u/message.c
@@ -356,7 +356,7 @@ static BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lpa
         wp.cx              = ps->wp.cx;
         wp.cy              = ps->wp.cy;
         wp.flags           = ps->wp.flags;
-        memcpy( &ps->wp, &wp, sizeof(wp) );
+        memcpy( ps, &wp, sizeof(wp) );
         break;
     }
     case WM_WINE_KEYBOARD_LL_HOOK:
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/869