nextcloud-desktop/shell_integration/windows/NCContextMenu/RegDelnode.h

#pragma once

#include <windows.h>
#include <stdio.h>
#include <strsafe.h>

// Stolen from the "Deleting a Key with Subkeys" example to replace
// RegDeleteTree which isn't available on WinXP.
// https://msdn.microsoft.com/en-us/library/ms724235(VS.85).aspx

//*************************************************************
//
//  RegDelnodeRecurse()
//
//  Purpose:    Deletes a registry key and all its subkeys / values.
//
//  Parameters: hKeyRoot    -   Root key
//              lpSubKey    -   SubKey to delete
//
//  Return:     TRUE if successful.
//              FALSE if an error occurs.
//
//*************************************************************

HRESULT RegDelnodeRecurse(HKEY hKeyRoot, LPTSTR lpSubKey)
{
	LPTSTR lpEnd;
	LONG lResult;
	DWORD dwSize;
	TCHAR szName[MAX_PATH];
	HKEY hKey;
	FILETIME ftWrite;

	// First, see if we can delete the key without having
	// to recurse.

	lResult = RegDeleteKey(hKeyRoot, lpSubKey);

	if (lResult == ERROR_SUCCESS)
		return lResult;

	lResult = RegOpenKeyEx(hKeyRoot, lpSubKey, 0, KEY_READ, &hKey);

	if (lResult != ERROR_SUCCESS)
		return lResult;

	// Check for an ending slash and add one if it is missing.

	lpEnd = lpSubKey + lstrlen(lpSubKey);

	if (*(lpEnd - 1) != TEXT('\\'))
	{
		*lpEnd = TEXT('\\');
		lpEnd++;
		*lpEnd = TEXT('\0');
	}

	// Enumerate the keys

	dwSize = MAX_PATH;
	lResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, nullptr,
		nullptr, nullptr, &ftWrite);

	if (lResult == ERROR_SUCCESS)
	{
		do {

			StringCchCopy(lpEnd, MAX_PATH * 2, szName);

			if (RegDelnodeRecurse(hKeyRoot, lpSubKey) != ERROR_SUCCESS) {
				break;
			}

			dwSize = MAX_PATH;

			lResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, nullptr,
				nullptr, nullptr, &ftWrite);

		} while (lResult == ERROR_SUCCESS);
	}

	lpEnd--;
	*lpEnd = TEXT('\0');

	RegCloseKey(hKey);

	// Try again to delete the key.

	lResult = RegDeleteKey(hKeyRoot, lpSubKey);
	return lResult;
}

//*************************************************************
//
//  RegDelnode()
//
//  Purpose:    Deletes a registry key and all its subkeys / values.
//
//  Parameters: hKeyRoot    -   Root key
//              lpSubKey    -   SubKey to delete
//
//  Return:     TRUE if successful.
//              FALSE if an error occurs.
//
//*************************************************************

HRESULT RegDelnode(HKEY hKeyRoot, LPTSTR lpSubKey)
{
	TCHAR szDelKey[MAX_PATH * 2];

	StringCchCopy(szDelKey, MAX_PATH * 2, lpSubKey);
	return RegDelnodeRecurse(hKeyRoot, szDelKey);

}