Since `_WD_FLAGS` is all WD flags and `WD_UNINITIALIZED` is actually one of them, I'd probably write this as:

```c
(((S) & (GIT_SUBMODULE_STATUS__WD_FLAGS & ~GIT_SUBMODULE_STATUS_WD_UNINITIALIZED)) == 0)
```

i.e. the status has any WD flag except for `WD_UNINITIALIZED`.  I realize they are functionally equivalent, but to me it feels better to update the mask of flags that matter instead of introducing an OR into the logic (although I realize that any sane compiler will generate the same code for both implementations).