addGrandTotals causes str_contains(): Deprecated functionality Passing null

[Hanmac]

Preconditions (*)

1. Version: 20.3.0+
2. Have Some Customer Orders for the Report

Steps to reproduce (*)

1. Open an Admin Report that has some Totals, but not all columns. Like report_customer/totals

Expected result (*)

1. [Screenshots, logs or description]
2. No warnings in system.log

Actual result (*)

1. [Screenshots, logs or description]
2. Deprecated functionality: str_contains(): Passing null to parameter #1 ($haystack) of type string is deprecated in app/code/core/Mage/Adminhtml/Block/Report/Grid.php

Explaination

This Grid Column in this Grid: Mage_Adminhtml_Block_Report_Customer_Totals_Grid

magento-lts/app/code/core/Mage/Adminhtml/Block/Report/Customer/Totals/Grid.php

Lines 45 to 49 in 6ceda6a

	$this->addColumn('name', [
	'header' => $this->__('Customer Name'),
	'sortable' => false,
	'index' => 'name'
	]);

Causes Problems in this function: Mage_Adminhtml_Block_Report_Grid::addGrandTotals

magento-lts/app/code/core/Mage/Adminhtml/Block/Report/Grid.php

Lines 414 to 424 in 6ceda6a

	foreach ($this->getColumns() as $key => $_column) {
	if (str_contains($_column->getTotal(), '/')) {
	list($t1, $t2) = explode('/', $_column->getTotal());
	if ($this->getGrandTotals()->getData($t2) != 0) {
	$this->getGrandTotals()->setData(
	$key,
	(float)$this->getGrandTotals()->getData($t1) / $this->getGrandTotals()->getData($t2)
	);
	}
	}
	}

An easy fix probably would be to check hasTotal() first? Ala:
$_column->hasTotal() && str_contains($_column->getTotal(), '/')