Merge branch '3.1-stable' into develop

Conflicts resolved:
	.travis.yml
	system/database/DB_query_builder.php
	system/helpers/captcha_helper.php
	system/libraries/Cache/drivers/Cache_redis.php
	system/libraries/Zip.php

7 files changed, 62 insertions, 8 deletions

diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index 642ff3a50..dcd6882c8 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -103,6 +103,18 @@ if ( ! function_exists('create_captcha'))
 			return FALSE;
 		}
 
+		if ($img_path === '' OR $img_url === '')
+		{
+			log_message('error', 'create_captcha(): $img_path and $img_url are required.');
+			return FALSE;
+		}
+
+		if ( ! is_dir($img_path) OR ! is_really_writable($img_path))
+		{
+			log_message('error', "create_captcha(): '{$img_path}' is not a dir, nor is it writable.");
+			return FALSE;
+		}
+
 		if ($img_url !== '' OR $img_path !== '')
 		{
 			if ($img_path === '' OR $img_url === '')
diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index 9dbe52844..9b082d11b 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -77,6 +77,13 @@ class CI_Cache_redis extends CI_Driver
 	 */
 	protected static $_delete_name;
 
+	/**
+	 * sRem()/sRemove() method name depending on phpRedis version
+	 *
+	 * @var	string
+	 */
+	protected static $_sRemove_name;
+
 	// ------------------------------------------------------------------------
 
 	/**
@@ -98,9 +105,19 @@ class CI_Cache_redis extends CI_Driver
 			return;
 		}
 
-		isset(static::$_delete_name) OR static::$_delete_name = version_compare(phpversion('redis'), '5', '>=')
-			? 'del'
-			: 'delete';
+		if ( ! isset(static::$_delete_name, static::$_sRemove_name))
+		{
+			if (version_compare(phpversion('redis'), '5', '>='))
+			{
+				static::$_delete_name  = 'del';
+				static::$_sRemove_name = 'sRem';
+			}
+			else
+			{
+				static::$_delete_name  = 'delete';
+				static::$_sRemove_name = 'sRemove';
+			}
+		}
 
 		$CI =& get_instance();
 
@@ -210,7 +227,7 @@ class CI_Cache_redis extends CI_Driver
 		}
 		else
 		{
-			$this->_redis->sRemove('_ci_redis_serialized', $id);
+			$this->_redis->{static::$_sRemove_name}('_ci_redis_serialized', $id);
 		}
 
 		return TRUE;
@@ -231,7 +248,7 @@ class CI_Cache_redis extends CI_Driver
 			return FALSE;
 		}
 
-		$this->_redis->sRemove('_ci_redis_serialized', $key);
+		$this->_redis->{static::$_sRemove_name}('_ci_redis_serialized', $key);
 
 		return TRUE;
 	}
diff --git a/system/libraries/Session/drivers/Session_files_driver.php b/system/libraries/Session/drivers/Session_files_driver.php
index 2899b7dec..d9966273b 100644
--- a/system/libraries/Session/drivers/Session_files_driver.php
+++ b/system/libraries/Session/drivers/Session_files_driver.php
@@ -196,6 +196,10 @@ class CI_Session_files_driver extends CI_Session_driver implements SessionHandle
 				$this->_fingerprint = md5('');
 				return '';
 			}
+
+			// Prevent possible data corruption
+			// See https://github.com/bcit-ci/CodeIgniter/issues/5857
+			clearstatcache(TRUE, $this->_file_path.$session_id);
 		}
 		// We shouldn't need this, but apparently we do ...
 		// See https://github.com/bcit-ci/CodeIgniter/issues/4039
diff --git a/system/libraries/Zip.php b/system/libraries/Zip.php
index 5fba1cf3a..4579e8c2b 100644
--- a/system/libraries/Zip.php
+++ b/system/libraries/Zip.php
@@ -406,13 +406,14 @@ class CI_Zip {
 			return FALSE;
 		}
 
+		// @see https://github.com/bcit-ci/CodeIgniter/issues/5864
 		$footer = $this->directory."\x50\x4b\x05\x06\x00\x00\x00\x00"
 			.pack('v', $this->entries) // total # of entries "on this disk"
 			.pack('v', $this->entries) // total # of entries overall
 			.pack('V', self::strlen($this->directory)) // size of central dir
 			.pack('V', self::strlen($this->zipdata)) // offset to start of central dir
 			."\x00\x00"; // .zip file comment length
-		return $this->zipdata . $footer;
+		return $this->zipdata.$footer;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index f5b68e08a..87fd6b9a8 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -135,6 +135,20 @@ Version 3.1.12
 
 Release Date: Not Released
 
+-  General Changes
+
+   -  Improved logging of error conditions in :doc:`CAPTCHA Helper <helpers/captcha_helper>` function :php:func:`create_captcha()`.
+   -  Added ``AUTO_INCREMENT`` support for Oracle 12.1+ to :doc:`Database Forge <database/forge>`.
+   -  Added ``FULL [OUTER] JOIN`` support to :doc:`Query Builder <database/query_builder>`.
+
+Bug fixes for 3.1.12
+====================
+
+-  Fixed a bug (#5834) - :doc:`Query Builder <database/query_builder>` method ``count_all_results()`` triggered an SQL error for queries with a ``HAVING`` clause.
+-  Fixed a bug (#5840) - :doc:`Cache Library <libraries/caching>` 'redis' driver triggered an ``E_DEPRECATED`` warning about ``sRemove()`` with phpRedis 5.
+-  Fixed a bug (#5857) - :doc:`Session <libraries/sessions>` data could be corrupted after a concurrent request write with the 'files' driver due to a filesize cache being incorrect.
+-  Fixed a bug (#5861) - :doc:`Cache Library <libraries/caching>` 'redis' driver would always use phpRedis 5 ``del()`` due to an incorrect version check.
+-  Fixed a bug (#5879) - :doc:`Profiler Library <general/profiling>` triggered an ``E_DEPRECATED`` warning on PHP 7.4+.
 
 Version 3.1.11
 ==============
@@ -149,7 +163,7 @@ Release Date: Sep 19, 2019
    -  Updated the :doc:`Session <libraries/sessions>` and :doc:`Cache <libraries/caching>` libraries' 'redis' driver to work with phpRedis 5.
 
 Bug fixes for 3.1.11
-====================
+--------------------
 
 -  Fixed a bug (#5681) - :doc:`Database Forge <database/forge>` method ``modify_column()`` produced erroneous SQL for ``DEFAULT`` attribute changes under PostgreSQL, Firebird.
 -  Fixed a bug (#5692) - :doc:`Database Forge <database/forge>` didn't handle column nullability with the 'oci8', 'pdo/oci' drivers.
diff --git a/user_guide_src/source/database/forge.rst b/user_guide_src/source/database/forge.rst
index 5af4f2248..c6cacb1b0 100644
--- a/user_guide_src/source/database/forge.rst
+++ b/user_guide_src/source/database/forge.rst
@@ -370,7 +370,7 @@ Class Reference
 	.. php:method:: drop_column($table, $column_name)
 
 		:param	string	$table: Table name
-		:param	array	$column_name: The column name to drop
+		:param	string	$column_name: The column name to drop
 		:returns:	TRUE on success, FALSE on failure
 		:rtype:	bool
 
diff --git a/user_guide_src/source/installation/upgrade_3112.rst b/user_guide_src/source/installation/upgrade_3112.rst
index 9c849d878..1000010ab 100644
--- a/user_guide_src/source/installation/upgrade_3112.rst
+++ b/user_guide_src/source/installation/upgrade_3112.rst
@@ -12,3 +12,9 @@ Replace all files and directories in your *system/* directory.
 
 .. note:: If you have any custom developed files in these directories,
 	please make copies of them first.
+
+Step 2: Replace config/user_agents.php
+================================
+
+This config file has received some updates. Please copy it to
+*application/config/user_agents.php*.