Administration: Reduce the chance that a PHP error message that occurs before the admin menu gets output is covered by the admin menu.

Props EmpireOfLight, afercia, Mte90, audrasjb, sunnyratilal

Fixes #35155
Built from https://develop.svn.wordpress.org/trunk@47745


git-svn-id: http://core.svn.wordpress.org/trunk@47521 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/admin-header.php

@@ -200,6 +200,11 @@ if ( $current_screen->is_block_editor() ) {
 	}
 }
 
+// Print a CSS class to make PHP errors visible.
+if ( error_get_last() && WP_DEBUG && WP_DEBUG_DISPLAY && ini_get( 'display_errors' ) ) {
+	$admin_body_class .= ' php-error';
+}
+
 ?>
 </head>
 <?php

wp-admin/css/admin-menu-rtl.css

@@ -14,6 +14,15 @@
 	z-index: 1; /* positive z-index to avoid elastic scrolling woes in Safari */
 }
 
+.php-error #adminmenuback {
+	position: absolute;
+}
+
+.php-error #adminmenuback,
+.php-error #adminmenuwrap {
+	margin-top: 2em;
+}
+
 #adminmenu {
 	clear: right;
 	margin: 12px 0;

wp-admin/css/admin-menu.css

@@ -13,6 +13,15 @@
 	z-index: 1; /* positive z-index to avoid elastic scrolling woes in Safari */
 }
 
+.php-error #adminmenuback {
+	position: absolute;
+}
+
+.php-error #adminmenuback,
+.php-error #adminmenuwrap {
+	margin-top: 2em;
+}
+
 #adminmenu {
 	clear: left;
 	margin: 12px 0;

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-alpha-47744';
+$wp_version = '5.5-alpha-47745';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.