Debug: The index_number parameter of the VLOOKUP function

[zsh0409]

This is:

- [*] a bug report
- [ ] a feature request
- [ ] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

The cell's function is set to VLOOKUP(A7,Sheet2!$A$1:$AG$50,{12,13,12},FALSE)

What is the expected behavior?

Return the data in the 12th column matched by Sheet2!$A$1:$AG$50

What is the current behavior?

VALUE!

What are the steps to reproduce?

Please provide a Minimal, Complete, and Verifiable example of code that exhibits the issue without relying on an external Excel file or a web server:

<?php

$spreadsheet->getActiveSheet()->toArray();

### What features do you think are causing the issue

- [ ] Reader
- [ ] Writer
- [ ] Styles
- [ ] Data Validations
- [*] Formula Calculations
- [ ] Charts
- [ ] AutoFilter
- [ ] Form Elements

### Does an issue affect all spreadsheet file formats? If not, which formats are affected?

### Which versions of PhpSpreadsheet and PHP are affected?
phpoffice/phpspreadsheet      1.28.0 

The code causing the error is in PhpOffice\PhpSpreadsheet\Calculation\LookupRef\LookupBase.php
The parameter index_number of the function validateIndexLookup failed to be validated
The current parameter is [12, 13, 12], then only the first value in the array should be taken

[oleibman]

@MarkBaker - this has something to with arrayEnabled, which I haven't studied enough to be familiar with. However, I think the following change fixes this problem, but I can't be sure that it doesn't break something else. If it works, I imagine it might need to be applied to other functions as well.

Existing code in Vlookup.php:

    public static function lookup($lookupValue, $lookupArray, $indexNumber, $notExactMatch = true)
    {
        if (is_array($lookupValue)) {
            return self::evaluateArrayArgumentsIgnore([self::class, __FUNCTION__], 1, $lookupValue, $lookupArray, $indexNumber, $notExactMatch);
        }

Changed code (one statement changed, the 'if' statement):

    public static function lookup($lookupValue, $lookupArray, $indexNumber, $notExactMatch = true)
    {
        if (is_array($lookupValue) || is_array($indexNumber)) {
            return self::evaluateArrayArgumentsIgnore([self::class, __FUNCTION__], 1, $lookupValue, $lookupArray, $indexNumber, $notExactMatch);
        }

[zsh0409]

thank you!