When SimplePie parses HTTP headers, it combines multiple values for the same header into a comma-separated string. `WP_SimplePie_File` overrides the parsing, but was leaving them as an array instead.
That lead to a fatal error in PHP 8, because other parts of the codebase ended up passing an array to a function that expected a string.
Props david.binda, litemotiv, inc2734, NicolasKulka, hellofromTonya, mbabker, skithund, SergeyBiryukov, desrosj, timothyblynjacobs.
Reviewed by SergeyBiryukov, iandunn.
Merges [49803] and [49805] to the 5.6 branch.
Fixes#51056. See #51956.
Built from https://develop.svn.wordpress.org/branches/5.6@49806
git-svn-id: http://core.svn.wordpress.org/branches/5.6@49529 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Prior to about 2013, many class methods lacked even access modifiers which made the `@access` notations that much more useful. Now that we've gotten to a point where the codebase is more mature from a maintenance perspective and we can finally remove these notations. Notable exceptions to this change include standalone functions notated as private as well as some classes still considered to represent "private" APIs.
See #41452.
Built from https://develop.svn.wordpress.org/trunk@41162
git-svn-id: http://core.svn.wordpress.org/trunk@41002 1a063a9b-81f0-0310-95a4-ce76da25c4cd