Import WXR fails with "Headers already sent"

[foolswisdom]

Import WXR fails with "Headers already sent"

ENV: WP 2.2 r5407
Similar failure on trunk r5407

1. Manage > Import > WordPress
2. Select file and click "Upload file and import" (Aise: the button label words should be capitalized)

Result:

Warning: Cannot modify header information - headers already sent by 
(output started at /var/www/wp/2.2/wp-admin/admin-header.php:16) in
/var/www/wp/2.2/wp-includes/functions.php on line 1335

Are you sure you want to do this?
No Yes

[ryan]

You're getting a nonce AYS. WXR importer calls check_admin_referer() which calls wp_nonce_ays() which calls wp_die() which sends headers. Since admin-header.php has been loaded, we get the warning.

[ryan]

(In [5410]) Don't send header from wp_die() if admin header already sent. fixes #4234 for 2.2.

[ryan]

(In [5411]) Don't send header from wp_die() if admin header already sent. fixes #4234 for 2.3.

[foolswisdom]

ENV: WP 2.2 r5411
Verified fixed.