Ticket #42193: 42193.patch

src/wp-admin/js/common.js

@@ -307 +307 @@
                 $sortables = $('.meta-box-sortables'),
                 wpResponsiveActive = false,
                 $adminbar = $( '#wpadminbar' ),
+                adminReadonlyTextarea = $( '.wp-admin textarea' ),
                 lastScrollPosition = 0,
                 pinnedMenuTop = false,
                 pinnedMenuBottom = false,
@@ -327 +328 @@
                 $(e.target).parent().siblings('a').get(0).click();
         });
 
+        adminReadonlyTextarea.focus( function() {
+                var $this = $( this );
+
+                if ( $this.is( '[readonly]' ) ) {
+                        $this.select();
+
+                        // Work-around for Chrome's issue.
+                        $this.mouseup( function() {
+                                // Prevent further mouseup intervention.
+                                $this.unbind( 'mouseup' );
+                                return false;
+                        });
+                }
+        });
+
         $( '#collapse-button' ).on( 'click.collapse-menu', function() {
                 var viewportWidth = getViewportWidth() || 961;