Props marijnkoopman, SergeyBiryukov, Clorith, azaozz. Merges [49704] to the 5.6 branch. Fixes #51863. Built from https://develop.svn.wordpress.org/branches/5.6@49707 git-svn-id: http://core.svn.wordpress.org/branches/5.6@49430 1a063a9b-81f0-0310-95a4-ce76da25c4cd