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Escape TinyMCE inline CSS in WP editor init - #3597
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Inline TinyMCE content CSS must be escaped before WordPress serializes it through _WP_Editors::_parse_init(), which wraps settings in JavaScript strings without escaping values. Use json_encode() for the normal path, keep a PHP 5.2-compatible fallback for non-UTF-8 CSS bytes, and cover the browser TinyMCE initialization path in the legacy boot suite.
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What changed
Escapes the CSS that Playground inlines into TinyMCE
content_stylethrough the sharedinline-tinymce-content-css.phpmu-plugin.The escape path uses PHP's
json_encode()to produce a JavaScript string body, strips the outer quotes because_WP_Editors::_parse_init()adds them itself, and keeps a small PHP 5.2-compatible fallback for unexpected encoder failures.The legacy WordPress boot suite now also checks the real browser new-post phase for classic TinyMCE bootstrap breakage and fails on
tinyMCEPreInit/content_style/truetypeJavaScript errors without waiting for TinyMCE itself to initialize.Why
_WP_Editors::_parse_init()serializes TinyMCE settings by concatenating JavaScript strings without escaping. Playground's inlined editor CSS can contain quotes, backslashes, newlines, and closing script sequences, for example Dashicons CSS withformat("truetype"). Those characters could break the inlinetinyMCEPreInitscript and leave the classic visual editor uninitialized.Validation
npm exec nx -- run playground-wordpress:lintnode --check packages/playground/wordpress/tests/test-legacy-wp-version-boot.mjsWP_ONLY=3.2,3.1,3.3,4.0,5.5,5.0,2.6,2.5,2.3,2.2,2.1,2.0,1.0 npm exec nx -- run playground-wordpress:test-legacy-wp-version-bootNotes
The sampled legacy browser matrix and lint pass.