Complete 3.0 upgrade notes about NULL returned on missing items
diff --git a/user_guide_src/source/installation/upgrade_300.rst b/user_guide_src/source/installation/upgrade_300.rst
index 0eafaf9..2e73ad1 100644
--- a/user_guide_src/source/installation/upgrade_300.rst
+++ b/user_guide_src/source/installation/upgrade_300.rst
@@ -145,29 +145,51 @@
(.+) // matches ANYTHING
(:any) // matches any character, except for '/'
-*************************************************
-Step 10: Check the calls to config->item() method
-*************************************************
+*************************************************************************
+Step 10: Many functions now return NULL instead of FALSE on missing items
+*************************************************************************
-This method now returns NULL instead of FALSE when the required config
-item doesn't exist.
+Many methods and functions now return NULL instead of FALSE when the required items don't exist:
-*****************************************************************************
-Step 11: Check the calls to Array Helper's element() and elements() functions
-*****************************************************************************
+ - :doc:`Config Class <../libraries/config>`
-The default return value of these functions, when the required elements
-don't exist, has been changed from FALSE to NULL.
+ - config->item()
+ - config->slash_item()
+
+ - :doc:`Input Class <../libraries/input>`
+
+ - input->get()
+ - input->post()
+ - input->get_post()
+ - input->cookie()
+ - input->server()
+ - input->input_stream()
+ - input->get_request_header()
+
+ - :doc:`Session Class <../libraries/sessions>`
+
+ - session->userdata()
+ - session->flashdata()
+
+ - :doc:`URI Class <../libraries/uri>`
+
+ - uri->segment()
+ - uri->rsegment()
+
+ - :doc:`Array Helper <../helpers/array_helper>`
+
+ - element()
+ - elements()
***********************************************************************
-Step 12: Check the calls to Directory Helper's directory_map() function
+Step 11: Check the calls to Directory Helper's directory_map() function
***********************************************************************
In the resulting array, directories now end with a trailing directory
separator (i.e. a slash, usually).
*************************************************************
-Step 13: Update usage of Database Forge's drop_table() method
+Step 12: Update usage of Database Forge's drop_table() method
*************************************************************
Up until now, ``drop_table()`` added an IF EXISTS clause by default or it didn't work
@@ -189,7 +211,7 @@
all drivers with the exception of ODBC.
***********************************************************
-Step 14: Change usage of Email library with multiple emails
+Step 13: Change usage of Email library with multiple emails
***********************************************************
The :doc:`Email Library <../libraries/email>` will automatically clear the
@@ -204,7 +226,7 @@
}
***************************************************
-Step 15: Update your Form_validation language lines
+Step 14: Update your Form_validation language lines
***************************************************
Two improvements have been made to the :doc:`Form Validation Library
@@ -235,7 +257,7 @@
later.
****************************************************************
-Step 16: Remove usage of (previously) deprecated functionalities
+Step 15: Remove usage of (previously) deprecated functionalities
****************************************************************
In addition to the ``$autoload['core']`` configuration setting, there's a