SC_HANDLE missing is_null()

[Huntragon]

I was updating a project that uses this crate to register and run an executable as a service in windows, and I ran into the issue that SC_HANDLE (returned from OpenServiceA) does not implement is_null() to see if the call executed successfully (which it did in the version I had before, 0.18.0).
As a workaround, I tried to do what the windows API says, to check if the return value is NULL (in which case it's not a valid handle). I've checked to see if there is a NULL constant defined somewhere and couldn't find it, so I'm guessing for now I have to use 0 directly (which I assume is what NULL means in the windows API, I don't have much experience with the API directly, only through the Rust crate)

[kennykerr]

SC_HANDLE is now just a type alias for isize consistent with the underlying Win32 definition. You can therefore just compare against 0 as that is the equivalent of NULL.

[travispaul]

For future travelers as of 0.30 SC_HANDLE has an is_invalid() method 🚀

[tim-weis]

This is true for the windows crate (SC_HANDLE) that restored newtypes for handles as of #1423 with version 0.30.0. In the windows-sys crate SC_HANDLE remains a type alias for isize and Kenny's comment above still applies here.