[ci skip] Update info on function_usable
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 3124dea..c6d42d9 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -449,7 +449,7 @@
- Changed ``_exception_handler()`` to respect php.ini *display_errors* setting.
- Added function :php:func:`is_https()` to check if a secure connection is used.
- Added function :php:func:`is_cli()` to replace the ``CI_Input::is_cli_request()`` method.
- - Added function :php:func:`function_usable()` to check if a function exists and is not disabled by `Suhosin <http://www.hardened-php.net/suhosin/>`.
+ - Added function :php:func:`function_usable()` to work around a bug in `Suhosin <http://www.hardened-php.net/suhosin/>`.
- Removed the third (`$php_error`) from function :php:func:`log_message()`.
- :doc:`Output Library <libraries/output>` changes include:
diff --git a/user_guide_src/source/general/common_functions.rst b/user_guide_src/source/general/common_functions.rst
index a1007cb..1babe5a 100644
--- a/user_guide_src/source/general/common_functions.rst
+++ b/user_guide_src/source/general/common_functions.rst
@@ -202,4 +202,9 @@
It is useful if you want to check for the availability of functions
such as ``eval()`` and ``exec()``, which are dangerous and might be
-disabled on servers with highly restrictive security policies.
\ No newline at end of file
+disabled on servers with highly restrictive security policies.
+
+.. note:: This function was introduced because Suhosin terminated
+ script execution, but this turned out to be a bug. A fix
+ has been available for some time (version 0.9.34), but is
+ unfortunately not released yet.
\ No newline at end of file