Add compatibility layer for array_column(), array_replace(), array_replace_recursive()
diff --git a/system/core/compat/array.php b/system/core/compat/array.php
new file mode 100644
index 0000000..b291703
--- /dev/null
+++ b/system/core/compat/array.php
@@ -0,0 +1,246 @@
+<?php
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 3.0
+ * @filesource
+ */
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+/**
+ * PHP ext/standard/array compatibility package
+ *
+ * @package		CodeIgniter
+ * @subpackage	CodeIgniter
+ * @category	Compatibility
+ * @author		Andrey Andreev
+ * @link		http://codeigniter.com/user_guide/
+ * @link		http://php.net/book.array
+ */
+
+// ------------------------------------------------------------------------
+
+if (is_php('5.5'))
+{
+	return;
+}
+
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('array_column'))
+{
+	/**
+	 * array_column()
+	 *
+	 * @link	http://php.net/array_column
+	 * @param	string	$array
+	 * @param	mixed	$column_key
+	 * @param	mixed	$index_key
+	 * @return	array
+	 */
+	function array_column(array $array, $column_key, $index_key = NULL)
+	{
+		if ( ! in_array($type = gettype($column_key), array('integer', 'string', 'NULL'), TRUE))
+		{
+			if ($type === 'double')
+			{
+				$column_key = (int) $column_key;
+			}
+			elseif ($type === 'object' && method_exists($column_key, '__toString'))
+			{
+				$column_key = (string) $column_key;
+			}
+			else
+			{
+				trigger_error('array_column(): The column key should be either a string or an integer', E_USER_WARNING);
+				return FALSE;
+			}
+		}
+
+		if ( ! in_array($type = gettype($index_key), array('integer', 'string', 'NULL'), TRUE))
+		{
+			if ($type === 'double')
+			{
+				$index_key = (int) $index_key;
+			}
+			elseif ($type === 'object' && method_exists($index_key, '__toString'))
+			{
+				$index_key = (string) $index_key;
+			}
+			else
+			{
+				trigger_error('array_column(): The index key should be either a string or an integer', E_USER_WARNING);
+				return FALSE;
+			}
+		}
+
+		$result = array();
+		foreach ($array as &$a)
+		{
+			if ($column_key === NULL)
+			{
+				$value = $a;
+			}
+			elseif (is_array($a) && array_key_exists($column_key, $a))
+			{
+				$value = $a[$column_key];
+			}
+			else
+			{
+				continue;
+			}
+
+			if ($index_key === NULL OR ! array_key_exists($index_key, $a))
+			{
+				$result[] = $value;
+			}
+			else
+			{
+				$result[$a[$index_key]] = $value;
+			}
+		}
+
+		return $result;
+	}
+}
+
+// ------------------------------------------------------------------------
+
+if (is_php('5.3'))
+{
+	return;
+}
+
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('array_replace'))
+{
+	/**
+	 * array_replace()
+	 *
+	 * @link	http://php.net/array_replace
+	 * @return	array
+	 */
+	function array_replace()
+	{
+		$arrays = func_get_args();
+
+		if (($c = count($arrays)) === 0)
+		{
+			trigger_error('array_replace() expects at least 1 parameter, 0 given', E_USER_WARNING);
+			return NULL;
+		}
+		elseif ($c === 1)
+		{
+			if ( ! is_array($arrays[0]))
+			{
+				trigger_error('array_replace(): Argument #1 is not an array', E_USER_WARNING);
+				return NULL;
+			}
+
+			return $arrays[0];
+		}
+
+		$array = array_shift($arrays);
+		$c--;
+
+		for ($i = 0, $c = count($arrays); $i < $c; $i++)
+		{
+			if ( ! is_array($arrays[$i]))
+			{
+				trigger_error('array_replace(): Argument #'.($i + 2).' is not an array', E_USER_WARNING);
+				return NULL;
+			}
+			elseif (empty($arrays[$i]))
+			{
+				continue;
+			}
+
+			foreach (array_keys($arrays[$i]) as $key)
+			{
+				$array[$key] = $arrays[$i][$key];
+			}
+		}
+
+		return $array;
+	}
+}
+
+// ------------------------------------------------------------------------
+
+if ( ! function_exists('array_replace_recursive'))
+{
+	/**
+	 * array_replace_recursive()
+	 *
+	 * @link	http://php.net/array_replace_recursive
+	 * @return	array
+	 */
+	function array_replace_recursive()
+	{
+		$arrays = func_get_args();
+
+		if (($c = count($arrays)) === 0)
+		{
+			trigger_error('array_replace_recursive() expects at least 1 parameter, 0 given', E_USER_WARNING);
+			return NULL;
+		}
+		elseif ($c === 1)
+		{
+			if ( ! is_array($arrays[0]))
+			{
+				trigger_error('array_replace_recursive(): Argument #1 is not an array', E_USER_WARNING);
+				return NULL;
+			}
+
+			return $arrays[0];
+		}
+
+		$array = array_shift($arrays);
+		$c--;
+
+		for ($i = 0, $c = count($arrays); $i < $c; $i++)
+		{
+			if ( ! is_array($arrays[$i]))
+			{
+				trigger_error('array_replace_recursive(): Argument #'.($i + 2).' is not an array', E_USER_WARNING);
+				return NULL;
+			}
+			elseif (empty($arrays[$i]))
+			{
+				continue;
+			}
+
+			foreach (array_keys($arrays[$i]) as $key)
+			{
+				$array[$key] = (is_array($arrays[$i][$key]) && isset($array[$key]) && is_array($array[$key]))
+					? array_replace_recursive($array[$key], $arrays[$i][$key])
+					: $arrays[$i][$key];
+			}
+		}
+
+		return $array;
+	}
+}
+
+/* End of file array.php */
+/* Location: ./system/core/compat/array.php */
\ No newline at end of file