Deprecated Functionality: preg_replace(): Passing null to parameter

Question

I have an issue;

1 exception(s): Exception #0 (Exception): Deprecated Functionality: preg_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in /var/www/html/vendor/magento/zendframework1/library/Zend/Db/Statement.php on line 222 Which is ;

// get a version of the SQL statement with all quoted
// values and delimited identifiers stripped out
// remove "foo\"bar"
$sql = preg_replace("/\"(\\\\\"|[^\"])*\"/Us", '', $sql);
// get the character for delimited id quotes,
// this is usually " but in MySQL is `
$d = $this->_adapter->quoteIdentifier('a');
$d = $d[0];
// get the value used as an escaped delimited id quote,
// e.g. \" or "" or \`
$de = $this->_adapter->quoteIdentifier($d);
$de = substr($de, 1, 2);
$de = preg_quote($de);
// Note: $de and $d where never used..., now they are:
(222) $sql = preg_replace("/$d($de|\\\\{2}|[^$d])*$d/Us", '', $sql);
return $sql;
}

My code is :

$_helper = $this->helper('Magento\Catalog\Helper\Output');
$_imagehelper = $this->helper('Magento\Catalog\Helper\Image');
$_product = $block->getProduct();

$specs = $_product->getAttributeText('specifications');
$specs = $specs = $this->helper('Magento\Catalog\Helper\Output')- 
>productAttribute($block->getProduct(), $block->getProduct()- 
>getSpecifications(), 'specifications');

$specs = trim( str_replace( array("\r\n","\r", "<br />" ),"", $specs));
$specs = trim( html_entity_decode( $specs ) );

Sample output of the my code:

Answer 1

Update below line :

$specs = trim( str_replace( array("\r\n","\r", "" ),"", $specs ) );

to

if($specs){
  $specs = trim( str_replace( array("\r\n","\r", "" ),"", $specs ) );
}

Answer 2

It's occurring due to the $sql variable being null. You need to check $sql variable contains a value or not.

Till PHP7.4 this method was runs without any error, from PHP8.1 it throws an error.

To solve this issue please add a (string) type for the $sql variable.

Please try the below way. I hope It'll not throw any errors.

echo $sql = preg_replace("/\"(\\\\\"|[^\"])*\"/Us", '', (string) $sql);

Thanks

Answer 3

I had the same error. In my case it was caused by MageWorx_SeoMarkup module. In my short time researching this I figured out that apparently they tried to get product description as if it were a dropdown type attribute (dropdown, multiple select, ...), but obviously it's not.

Disabling everything related to description in this module solved the issue for me.