win32u: Pack messages in WH_CALLWNDPROCRET hooks.

dlls/user32/hook.c

@@ -495,6 +495,18 @@ BOOL WINAPI User32CallWindowsHook( struct win_hook_params *params, ULONG size )
                 ret_size = 0;
                 break;
             }
+        case WH_CALLWNDPROCRET:
+            if (ret_size > sizeof(CWPRETSTRUCT))
+            {
+                CWPRETSTRUCT *cwpret = (CWPRETSTRUCT *)params->lparam;
+                size_t offset = (lparam_offset + sizeof(*cwpret) + 15) & ~15;
+                void *buffer = (char *)params + offset;
+
+                unpack_message( cwpret->hwnd, cwpret->message, &cwpret->wParam, &cwpret->lParam,
+                                &buffer, size - offset, !params->prev_unicode );
+                ret_size = 0;
+                break;
+            }
         }
     }
     if (params->module[0] && !(proc = get_hook_proc( proc, params->module, &free_module )))

dlls/win32u/hook.c

@@ -295,6 +295,13 @@ static LRESULT call_hook( struct win_hook_params *info, const WCHAR *module, siz
                                        cwp->message, cwp->lParam, ansi );
                 }
                 break;
+            case WH_CALLWNDPROCRET:
+                {
+                    CWPRETSTRUCT *cwpret = (CWPRETSTRUCT *)((char *)params + lparam_offset);
+                    pack_user_message( (char *)params + message_offset, message_size,
+                                       cwpret->message, cwpret->lParam, ansi );
+                }
+                break;
             }
         }
 

dlls/wow64win/user.c

@@ -766,6 +766,15 @@ static UINT hook_lparam_64to32( int id, int code, const void *lp, size_t size, v
             cwpret32.message = cwpret->message;
             cwpret32.hwnd    = HandleToUlong( cwpret->hwnd );
             memcpy( lp32, &cwpret32, sizeof(cwpret32) );
+            if (size > sizeof(*cwpret))
+            {
+                const size_t offset64 = (sizeof(*cwpret) + 15) & ~15;
+                const size_t offset32 = (sizeof(cwpret32) + 15) & ~15;
+                size = packed_message_64to32( cwpret32.message,
+                                              (const char *)lp + offset64,
+                                              (char *)lp32 + offset32, size - offset64 );
+                return offset32 + size;
+            }
             return sizeof(cwpret32);
         }