PHP8.1 compatibility fixes in referrers plugin #19127
Description
With Matomo 4.9.0, I see lots of these warnings:
1.
WARNING Referrers
plugins/Referrers/Columns/Base.php(525):
Deprecated - mb_strtolower(): Passing null to parameter #1 ($string) of type string is deprecated
2.
WARNING Referrers
plugins/Referrers/Columns/Base.php(478):
Deprecated - urldecode(): Passing null to parameter #1 ($string) of type string is deprecated
Problem 1 I solved temporarily by replacing
$this->keywordReferrerAnalyzed = mb_strtolower($this->keywordReferrerAnalyzed);
with
$this->keywordReferrerAnalyzed = mb_strtolower($this->keywordReferrerAnalyzed ?? '');
But I am not sure this is the best fix.