What does OpenProcess do when it cannot find a process with the given PID?

OpenProcess_PidNotFound.dib

#!meta

{"kernelInfo":{"defaultKernelName":"csharp","items":[{"aliases":[],"name":"csharp"}]}}

#!csharp

/** Q: What does OpenProcess do when it cannot find a process with the given PID?
    A: Returns a null handle and writes ERROR_SUCCESS (0) to "LastError"
 */

using Microsoft.Win32.SafeHandles;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Runtime.Versioning;

HANDLE handle = OpenProcess(PROCESS_ACCESS_RIGHTS.PROCESS_ALL_ACCESS, (BOOL)false, 99999);
handle.Display();
/** Submission#14+HANDLE
    IsNull	True
    Value	0
*/
Win32Exception err = new();
Console.WriteLine("P/Invoke status: " + err.ToString() + Environment.NewLine + Marshal.GetLastPInvokeError());
/** P/Invoke status: System.ComponentModel.Win32Exception (0x80004005): The operation completed successfully.
0
*/

public readonly partial struct HANDLE : IEquatable<HANDLE>
{
    public readonly IntPtr Value;
    public HANDLE(IntPtr value) => this.Value = value;

    public static HANDLE Null => default;

    public bool IsNull => Value == default;
    public static implicit operator IntPtr(HANDLE value) => value.Value;
    public static explicit operator HANDLE(IntPtr value) => new HANDLE(value);
    public static bool operator ==(HANDLE left, HANDLE right) => left.Value == right.Value;
    public static bool operator !=(HANDLE left, HANDLE right) => !(left == right);

    public bool Equals(HANDLE other) => this.Value == other.Value;

    public override bool Equals(object obj) => obj is HANDLE other && this.Equals(other);

    public override int GetHashCode() => this.Value.GetHashCode();
}

public readonly partial struct BOOL : IEquatable<BOOL>
{
    public readonly int Value;
    public BOOL(int value) => this.Value = value;
    public static implicit operator int(BOOL value) => value.Value;
    public static explicit operator BOOL(int value) => new BOOL(value);
    public static bool operator ==(BOOL left, BOOL right) => left.Value == right.Value;
    public static bool operator !=(BOOL left, BOOL right) => !(left == right);

    public bool Equals(BOOL other) => this.Value == other.Value;

    public override bool Equals(object obj) => obj is BOOL other && this.Equals(other);

    public override int GetHashCode() => this.Value.GetHashCode();
    public BOOL(bool value) => this.Value = value ? 1 : 0;
    public static implicit operator bool(BOOL value) => value.Value != 0;
    public static implicit operator BOOL(bool value) => new BOOL(value);
}

[Flags]
public enum PROCESS_ACCESS_RIGHTS : uint
{
    PROCESS_TERMINATE = 0x00000001,
    PROCESS_CREATE_THREAD = 0x00000002,
    PROCESS_SET_SESSIONID = 0x00000004,
    PROCESS_VM_OPERATION = 0x00000008,
    PROCESS_VM_READ = 0x00000010,
    PROCESS_VM_WRITE = 0x00000020,
    PROCESS_DUP_HANDLE = 0x00000040,
    PROCESS_CREATE_PROCESS = 0x00000080,
    PROCESS_SET_QUOTA = 0x00000100,
    PROCESS_SET_INFORMATION = 0x00000200,
    PROCESS_QUERY_INFORMATION = 0x00000400,
    PROCESS_SUSPEND_RESUME = 0x00000800,
    PROCESS_QUERY_LIMITED_INFORMATION = 0x00001000,
    PROCESS_SET_LIMITED_INFORMATION = 0x00002000,
    PROCESS_ALL_ACCESS = 0x001FFFFF,
    PROCESS_DELETE = 0x00010000,
    PROCESS_READ_CONTROL = 0x00020000,
    PROCESS_WRITE_DAC = 0x00040000,
    PROCESS_WRITE_OWNER = 0x00080000,
    PROCESS_SYNCHRONIZE = 0x00100000,
    PROCESS_STANDARD_RIGHTS_REQUIRED = 0x000F0000,
}

/// <summary>Opens an existing local process object.</summary>
/// <param name="dwDesiredAccess">
///     <para>The access to the process object. This access right is checked against the  security descriptor for the process. This parameter can be one or more of the <a href="https://docs.microsoft.com/windows/desktop/ProcThread/process-security-and-access-rights">process access rights</a>. If the caller has enabled the SeDebugPrivilege privilege, the requested access is  granted regardless of the contents of the security descriptor.</para>
///     <para><see href="https://docs.microsoft.com/windows/win32/api//processthreadsapi/nf-processthreadsapi-openprocess#parameters">Read more on docs.microsoft.com</see>.</para>
/// </param>
///     <param name="bInheritHandle">If this value is TRUE, processes created by this process will inherit the handle. Otherwise, the processes do not inherit this handle.</param>
///     <param name="dwProcessId">
///     <para>The identifier of the local process to be opened. If the specified process is the System Idle Process (0x00000000), the function fails and the last error code is `ERROR_INVALID_PARAMETER`. If the specified process is the System process or one of the Client Server Run-Time Subsystem (CSRSS) processes, this function fails and the last error code is `ERROR_ACCESS_DENIED` because their access restrictions prevent user-level code from opening them. If you are using <a href="https://docs.microsoft.com/windows/desktop/api/processthreadsapi/nf-processthreadsapi-getcurrentprocessid">GetCurrentProcessId</a> as an argument to this function, consider using <a href="https://docs.microsoft.com/windows/desktop/api/processthreadsapi/nf-processthreadsapi-getcurrentprocess">GetCurrentProcess</a> instead of OpenProcess, for improved performance.</para>
///     <para><see href="https://docs.microsoft.com/windows/win32/api//processthreadsapi/nf-processthreadsapi-openprocess#parameters">Read more on docs.microsoft.com</see>.</para>
/// </param>
/// <returns>
///     <para>If the function succeeds, the return value is an open handle to the specified process. If the function fails, the return value is NULL. To get extended error information, call <a href="/windows/desktop/api/errhandlingapi/nf-errhandlingapi-getlasterror">GetLastError</a>.</para>
/// </returns>
/// <remarks>
///     <para><see href="https://docs.microsoft.com/windows/win32/api//processthreadsapi/nf-processthreadsapi-openprocess">Learn more about this API from docs.microsoft.com</see>.</para>
/// </remarks>
[DllImport("KERNEL32.dll", ExactSpelling = true, SetLastError = true)]
[DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
[SupportedOSPlatform("windows5.1.2600")]
public static extern HANDLE OpenProcess(PROCESS_ACCESS_RIGHTS dwDesiredAccess, BOOL bInheritHandle, uint dwProcessId);