Comment 3 for bug 1455995

Here's the workaround for drush (probably need to apply to /etc/php5/apache2/php.ini as well):

--- etc/php5/cli/php.ini.bak 2015-05-17 19:49:14.893316566 -0700
+++ etc/php5/cli/php.ini 2015-05-17 19:50:58.822103819 -0700
@@ -1698,7 +1698,7 @@
 ; If empty, default_charset or input_encoding or mbstring.input is used.
 ; The precedence is: default_charset < intput_encoding < mbsting.http_input
 ; http://php.net/mbstring.http-input
-;mbstring.http_input =
+mbstring.http_input = pass

 ; Use of this INI entry is deprecated, use global output_encoding instead.
 ; http output encoding.
@@ -1708,7 +1708,7 @@
 ; To use an output encoding conversion, mbstring's output handler must be set
 ; otherwise output encoding conversion cannot be performed.
 ; http://php.net/mbstring.http-output
-;mbstring.http_output =
+mbstring.http_output = pass

 ; enable automatic encoding translation according to
 ; mbstring.internal_encoding setting. Input chars are