Friendly overload for `MsiGetSummaryInformation()` can't accept a null hDatabase value.

[mjr4077au]

Actual behavior

From the docs as it's all I have to go on:

If the database specified by the MsiGetSummaryInformation function is not open, you must specify 0 for hDatabase and specify the path to the database in szDatabasePath. If the database is open, you must set szDatabasePath to 0.

If a value of uiUpdateCount greater than 0 is used to open an existing summary information stream, MsiSummaryInfoPersist must be called before closing the phSummaryInfo handle. Failing to do this will lose the existing stream information.

Expected behavior

That this SafeHandle parameter accepts null on the friendly overload and handles it interally like other SafeHandle types do.

Repro steps

1. NativeMethods.txt content:

MsiGetSummaryInformation

2. NativeMethods.json content (if present): N/A

3. Any of your own code that should be shared? N/A

Context

• CsWin32 version: 0.3.257
• Win32Metadata version (if explicitly set by project): N/A
• Target Framework: net472
• LangVersion (if explicitly set by project): N/A

[jevansaks]

If the parameter is not [Optional] then the friendly method does not allow the SafeHandle to be null. In the meantime you can create a SafeHandle instance that holds 0 in order to pass 0 through the friendly overload.

You can double check the annotations in the headers in the win32metadata repo: https://github.com/search?q=repo%3Amicrosoft%2Fwin32metadata%20MsiGetSummaryInformation&type=code

It looks like most (all?) of the MSI functions don't have annotations so the default is [in, out] and nothing is optional.

[mjr4077au]

I wrap all of my calls to native methods so they throw Win32Exceptions upon errors, so I've covered this in my wrapper and just send in a SafeFileHandle with IntPtr.Zero if I send in a null here.

Still though, it'd be good to see it addressed in the metadata as 0 is effectively nullptr, so I feel it should be expressed that way in a way that CsWin32 can build upon.

Thanks for checking this out as per usual, and good lad for staying off the tools on the weekend 😁