Only one product deleted per iteration

This seems to be because of the $maxium_time setting in the wc_remove_all_products_display_default_tab() function. ini_get(‘max_execution_time’) only returns a value if max_execution_time is set in the php.ini file, which isn’t always the case on some servers. If you have max_execution_time set to 0 (unlimited), this will also cause this bug.

Checking for a false or 0 $maximum_time and adjusting as appropriate fixes this:

$maximum_time = ini_get('max_execution_time');

// PHP default if max_execution_time could not be retrieved
if ( $maximum_time === false ) {
    $maximum_time = 30;
}

// Set a suitably high default if max_execution_time is unlimited
if ( $maximum_time <= 0 ) {
    $maximum_time = 86400;
}