CATEGORIES only comma escaped list

[chris5560]

VObject version 4.5.3

According to RFC 6350 (6.7.1), CATEGORIES should be a comma separated list.
But if you call $vCard->add('CATEGORIES', 'INTERNET,IETF,INDUSTRY')
then you will get 'CATEGORIES:INTERNET,IETF,INDUSTRY', which is a comma escaped list.
If you comment out the line (135) ',' => '.', in getRawMimeDirValue() function
inside lib/Property/Text.php file, it works correctly.
Unfortunately, I don't have the overview of your library to assess the global impact of a change.
Also, I haven't found any articles on the web about what other command to add CATEGORIES to a VCard.
Thanks for your support.

[gharlan]

Are some backslashes missing in your code snippets?

Did you try to add the categories by array?
$vCard->add('CATEGORIES', ['INTERNET', 'IETF', 'INDUSTRY'])