[wp-trac] [WordPress Trac] #46090: Always include the X-UA-Compatible header in `_wp_admin_html_begin()`.

[WordPress Trac]

#46090: Always include the X-UA-Compatible header in `_wp_admin_html_begin()`.
----------------------------+-----------------------------
 Reporter:  peterwilsoncc   |      Owner:  (none)
     Type:  defect (bug)    |     Status:  new
 Priority:  normal          |  Milestone:  Awaiting Review
Component:  Administration  |    Version:
 Severity:  normal          |   Keywords:
  Focuses:                  |
----------------------------+-----------------------------
 `_wp_admin_html_begin()` uses the following code to avoid compatibility
 mode in Internet Explorer.

 {{{#!php
 <?php
 global $is_IE;
 if ( $is_IE ) {
         @header( 'X-UA-Compatible: IE=edge' );
 }
 }}}

 As the tag is benign in most cases, the condition can be removed and the
 HTTP header always included.

 In `wp-includes/vars.php` the compatibility header is set to use chrome
 frame in the admin (and on the front end if a developer desires).

 In the dashboard, these can combined to become `X-UA-Compatible: IE=edge,
 chrome=1`.

 Once IE11 use drops further, they can be deleted but until then it's a
 nice trip down memory lane.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/46090>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform