PrivateExtractIcons method incorrectly claims piconid parameter is an array

[Craftplacer]

Actual behavior

PrivateExtractIcons is failing because nIcons is set to zero, the only way to set it to a valid value is to use the "unmanaged" method overload (that uses unsafe pointers). I don't know why nIcons isn't part of the managed function signature.

In this screenshot, there's a call visible done by a referenced DLL (shell32.dll) that calls the function correctly, while the .NET runtime (user code, coreclr.dll) is calling the function with nIcons set to 0 (also causing the entry to be highlighted as yellow indicating an error).

Expected behavior

To have uint nIcons inside the method overload using managed objects:

PrivateExtractIcons(string szFileName, int nIconIndex, int cxIcon, int cyIcon, out DestroyIconSafeHandle phicon, Span<uint> piconid, /*uint nIcons*/, uint flags)

Repro steps

1. NativeMethods.txt content:

PrivateExtractIcons

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

var result = PInvoke.PrivateExtractIcons(@"C:\Windows\system32\shell32.dll", -33, 32, 32, out var hIcon, null, 0);

In this example hIcon is NULL and the result is also 0, indicating this function did nothing or has failed.

Context

• CsWin32 version: 0.1.506-beta
• Target Framework: net5.0-windows

[AArnott]

The parameter is removed from the friendly overload because it can be inferred from the length of the phicon array.
However the metadata is buggy for this method. It claims that both phicon and piconid are arrays, both of which have a length set by nIcons. But per the docs piconid is not an array at all.
When the metadata is fixed, the missing parameter in the friendly overload will still be missing, but you'll be able to set its value by allocating the proper span for the phicon argument.