Encoding errors in plugins updating subsystem

[sergey.s.betke@…]

When the option default_charset in php.ini (for example - windows-1251) other than blog encoding (for example - UTF-8), whe have troubles.

WordPress version

Latest WordPress files - 3.3-RC1-19537

browser

MS IE9, Google Chrome

Reproducing the problems

• set in php.ini (or in htaccess) default_charset to windows-1251 (or any other, not UTF-8 in this example)
• set wordpress option blog_charset to UTF-8
• go to /wp-admin/update-core.php
• update Your plugins. I see wrong encoding in iframe.

plugins and themes

This trouble is exist on default wordpress installation, with any plugins, on default theme

Test environment

• IIS 7
• PHP 5.3.6
• MySQL 5.1
• proxy - MS ISA Server
• Test server - ​http://test.www.novgaro.ru, account - testuser, password - testuser. (You can login to this test server).

Confirmed on Apache 2.2.4 with PHP 5.2.14 as well: 19454.iframe.png​.

AddDefaultCharset utf-8 in .htaccess doesn't help.

19454.2.diff​ is the refreshed patch. Not sure if the additional headers are necessary though. 19454.charset-only.diff​ just fixes the charset issue.

Related: #4794, #19448

Moving things into _wp_admin_html_begin() can result in dupes. The six places that call this function need to be audited.

19454.3.diff​ only adds the charset to iframe_header(). The rest appears to be already handled.

In [21538]:

Send Content-Type with charset for iframe_header(). Props SergeyBiryukov, sergey.s.betke@…. fixes #19454