MsgWaitForMultipleObjects went untested in last commit

Author: Szwagi

lib/std/os/windows/user32.zig

@@ -25,6 +25,7 @@ const LRESULT = windows.LRESULT;
 const HICON = windows.HICON;
 const LPARAM = windows.LPARAM;
 const POINT = windows.POINT;
+const HANDLE = windows.HANDLE;
 const HCURSOR = windows.HCURSOR;
 const HBRUSH = windows.HBRUSH;
 
@@ -1138,9 +1139,10 @@ pub fn waitMessage() !void {
     if (WaitMessage() == 0) return windows.unexpectedError(GetLastError());
 }
 
-pub extern "user32" fn MsgWaitForMultipleObjects(nCount: DWORD, pHandles: ?[*]const anyopaque, fWaitAll: BOOL, dwMilliseconds: DWORD, dwWakeMask: DWORD) callconv(WINAPI) DWORD;
-pub fn msgWaitForMultipleObjects(handles: ?[]*const anyopaque, waitAll: bool, dwMilliseconds: DWORD, dwWakeMask: DWORD) !DWORD {
-    const value = MsgWaitForMultipleObjects(handles.?.len orelse 0, handles.?.ptr, @intFromBool(waitAll), dwMilliseconds, dwWakeMask);
+pub extern "user32" fn MsgWaitForMultipleObjects(nCount: DWORD, pHandles: ?[*]const HANDLE, fWaitAll: BOOL, dwMilliseconds: DWORD, dwWakeMask: DWORD) callconv(WINAPI) DWORD;
+pub fn msgWaitForMultipleObjects(handles: ?[]const HANDLE, waitAll: bool, dwMilliseconds: DWORD, dwWakeMask: DWORD) !DWORD {
+    const value = if (handles) |h| MsgWaitForMultipleObjects(@intCast(h.len), h.ptr, @intFromBool(waitAll), dwMilliseconds, dwWakeMask)
+        else MsgWaitForMultipleObjects(0, null, @intFromBool(waitAll), dwMilliseconds, dwWakeMask);
     if (value != windows.WAIT_FAILED) return value;
 
     switch (GetLastError()) {