The SafeHandle overload for `InitializeAcl()` is incorrect.

[mjr4077au]

Actual behavior

This P/Invoke wrapper is sending a pointer to a fixed address of the out'd ACL variable when this P/Invoke expects a buffer allocated with LocalAlloc be allocated and sent through first.

internal static unsafe winmdroot.Foundation.BOOL InitializeAcl(out winmdroot.Security.ACL pAcl, uint nAclLength, winmdroot.Security.ACE_REVISION dwAclRevision)
{
	fixed (winmdroot.Security.ACL* pAclLocal = &pAcl)
	{
		winmdroot.Foundation.BOOL __result = PInvoke.InitializeAcl(pAclLocal, nAclLength, dwAclRevision);
		return __result;
	}
}

Expected behavior

This wrapper should be doing a LocalAlloc() allocation to the specified size of nAclLength, sending a pointer for this through to InitializeAcl(), then the pAcl parameter should be out'ing a LocalFreeSafeHandle type to work with.

Repro steps

1. NativeMethods.txt content:

InitializeAcl

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

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

Context

• CsWin32 version: Latest
• Win32Metadata version: N/A
• Target Framework: net472
• LangVersion: N/A

[jevansaks]

CsWin32 should be projecting this as a Span where the length of the span in bytes is equal to nAclLength. Then the caller can make sure they have created a buffer large enough to handle this. I'll look into why this is not happening.

[jevansaks]

I think the only safe way to project this is to have the ACL parameter be typed as Span<byte>, and the friendly method would be:

internal static unsafe winmdroot.Foundation.BOOL InitializeAcl(Span<byte> pAcl, winmdroot.Security.ACE_REVISION dwAclRevision)
{
	fixed (byte* pAclLocal = pAcl)
	{
		winmdroot.Foundation.BOOL __result = PInvoke.InitializeAcl((winmdroot.Security.ACL* )pAclLocal, (uint )pAcl.Length, dwAclRevision);
		return __result;
	}
}

Callers would calculate the right size of buffer and then afterwards could reinterpret that as an ACL:

Span<byte> aclBytes = byte[...calculatedlength...]
InitializeAcl(aclBytes, ...)

ref ACL acl = ref MemoryMarshal.AsRef<ACL>(buffer);
// Go do something with the acl struct...

This is what I plan to do unless someone can recommend a better way. :) (@Sergio0694 , @jkoritzinsky, @AaronRobinsonMSFT ?)