1.5.2: take shared-menu 1.2.1, which centres the glyph

Kristian reported the infinity sign sitting above centre in the admin menu on
the live shop. Security traced it to WordPress's own stylesheet rather than
adjusting it by eye: #adminmenu div.wp-menu-image is 36x34 and its :before
carries padding 7px 0, which is exactly 7 + 20 + 7 for a 20px dashicon at
line-height 1. The 1.2.0 rule set line-height 1.4 and inherited that padding,
so the pseudo-element was 42px tall inside a 34px parent.

1.2.1 reproduces the box, drops the padding and centres with flex — geometry
rather than a nudge, because U+221E sits on the maths axis instead of filling
its em box.

It is the same half-done abstraction as the escaping fix: the filter made the
character configurable and left the geometry tuned for one specific character.
Nothing could fail, because the only value anyone ever passed was the one it
was tuned for.

Verified before copying, including the part that makes the check meaningful:
Security predicted php -w WOULD differ this round, since the executable code
changed — so equal stripped hashes would have meant the wrong file. They
differ, and the diff is the version constant plus the CSS geometry, with
wpmgr_css_escape untouched.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

includes/shared-menu.php

@@ -69,7 +69,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 }
 
 if ( ! defined( 'WPMGR_MENU_VERSION' ) ) {
-	define( 'WPMGR_MENU_VERSION', '1.2.0' );
+	define( 'WPMGR_MENU_VERSION', '1.2.1' );
 }
 
 if ( ! defined( 'WPMGR_MENU_SLUG' ) ) {
@@ -160,6 +160,23 @@ if ( ! function_exists( 'wpmgr_ensure_menu' ) ) {
 	 * `font-family` has to be overridden: WordPress sets the icon wrapper to
 	 * the Dashicons font, and Dashicons has no infinity glyph, so inheriting
 	 * it renders nothing at all.
+	 *
+	 * 🔴 The box is WordPress's own, measured rather than guessed, and the
+	 * glyph is centred in it geometrically rather than nudged.
+	 *
+	 * wp-admin/css/admin-menu.css sets `#adminmenu div.wp-menu-image` to
+	 * 36x34, and `div.wp-menu-image:before` to `padding: 7px 0` — which is
+	 * exactly 7 + 20 + 7 for a 20px dashicon on `line-height: 1`. The first
+	 * version of this rule set `line-height: 1.4` and inherited that padding,
+	 * making the line box 28px and the whole pseudo-element 42px inside a 34px
+	 * parent. Kristian reported the result: the glyph sitting above centre.
+	 *
+	 * So: reproduce the 36x34 box, drop the padding that only existed to
+	 * position a 20px line inside it, and centre with flex. That matters more
+	 * for an arbitrary glyph than for a dashicon — U+221E sits on the maths
+	 * axis rather than filling its em box, so any rule that positions by
+	 * line-height and padding is positioning the box and hoping about the
+	 * glyph. `align-items: center` centres what is actually drawn.
 	 */
 	function wpmgr_menu_glyph_style() {
 		$glyph = apply_filters( 'wpmgr_menu_glyph', '∞' );
@@ -170,7 +187,7 @@ if ( ! function_exists( 'wpmgr_ensure_menu' ) ) {
 
 		// phpcs:disable WordPress.Security.EscapeOutput.OutputNotEscaped -- the slug is reduced to [a-z0-9_-] and the glyph to CSS numeric escapes; both are escaped for the context they are printed in, which is CSS rather than HTML.
 		printf(
-			'<style>#adminmenu .toplevel_page_%1$s .wp-menu-image::before{content:"%2$s";font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;font-size:20px;font-weight:400;line-height:1.4}</style>',
+			'<style>#adminmenu .toplevel_page_%1$s .wp-menu-image::before{content:"%2$s";font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;font-size:20px;font-weight:400;display:flex;align-items:center;justify-content:center;width:36px;height:34px;padding:0;line-height:1}</style>',
 			preg_replace( '/[^a-z0-9_-]/', '', strtolower( WPMGR_MENU_SLUG ) ),
 			wpmgr_css_escape( $glyph )
 		);