Fix QB delete() for multiple tables with where()

Reported via the forums: http://forum.codeigniter.com/thread-61774.html
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 859f9f5..a8b5b35 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -2092,10 +2092,13 @@
 		}
 		elseif (is_array($table))
 		{
+			empty($where) && $reset_data = FALSE;
+
 			foreach ($table as $single_table)
 			{
 				$this->delete($single_table, $where, $limit, $reset_data);
 			}
+
 			return;
 		}
 		else
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 073f687..edbcf2f 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -45,7 +45,7 @@
 -  Fixed a bug (#3922) - :doc:`Email <libraries/email>` and :doc:`XML-RPC <libraries/xmlrpc>` libraries could enter an infinite loop due to `PHP bug #39598 <https://bugs.php.net/bug.php?id=39598>`_.
 -  Fixed a bug (#3913) - :doc:`Cache Library <libraries/caching>` didn't work with the direct ``$this->cache->$driver_name->method()`` syntax with Redis and Memcache(d).
 -  Fixed a bug (#3932) - :doc:`Query Builder <database/query_builder>` didn't properly compile WHERE and HAVING conditions for field names that end with "and", "or".
-
+-  Fixed a bug in :doc:`Query Builder <database/query_builder>` where ``delete()`` didn't properly work on multiple tables with a WHERE condition previously set via ``where()``.
 
 Version 3.0.0
 =============