5 files changed, 98 insertions, 3 deletions
diff --git a/phpBB/phpbb/mimetype/content_guesser.php b/phpBB/phpbb/mimetype/content_guesser.php
index 21631ae6d3..ffaed9136a 100644
--- a/phpBB/phpbb/mimetype/content_guesser.php
+++ b/phpBB/phpbb/mimetype/content_guesser.php
@@ -21,7 +21,7 @@ if (!defined('IN_PHPBB'))
 * @package mimetype
 */
 
-class content_guesser implements guesser_interface
+class content_guesser extends guesser_base
 {
 	/**
 	* @inheritdoc
diff --git a/phpBB/phpbb/mimetype/extension_guesser.php b/phpBB/phpbb/mimetype/extension_guesser.php
index 8cca974efc..f9459c84ec 100644
--- a/phpBB/phpbb/mimetype/extension_guesser.php
+++ b/phpBB/phpbb/mimetype/extension_guesser.php
@@ -21,7 +21,7 @@ if (!defined('IN_PHPBB'))
 * @package mimetype
 */
 
-class extension_guesser implements guesser_interface
+class extension_guesser extends guesser_base
 {
 	/**
 	* @var file extension map
diff --git a/phpBB/phpbb/mimetype/guesser.php b/phpBB/phpbb/mimetype/guesser.php
index 231b75f604..753fd65b0d 100644
--- a/phpBB/phpbb/mimetype/guesser.php
+++ b/phpBB/phpbb/mimetype/guesser.php
@@ -24,6 +24,11 @@ if (!defined('IN_PHPBB'))
 class guesser
 {
 	/**
+	* @const Default priority for mimetype guessers
+	*/
+	const PRIORITY_DEFAULT = 0;
+
+	/**
 	* @var mimetype guessers
 	*/
 	protected $guessers;
@@ -39,7 +44,7 @@ class guesser
 	}
 
 	/**
-	* Register MimeTypeGuessers
+	* Register MimeTypeGuessers and sort them by priority
 	*
 	* @param array $mimetype_guessers Mimetype guesser service collection
 	*
@@ -68,6 +73,34 @@ class guesser
 		{
 			throw new \LogicException('No mimetype guesser supplied.');
 		}
+
+		// Sort guessers by priority
+		usort($this->guessers, array($this, 'sort_priority'));
+	}
+
+	/**
+	* Sort the priority of supplied guessers
+	* This is a compare function for usort. A guesser with higher priority
+	* should be used first and vice versa. usort() orders the array values
+	* from low to high depending on what the comparison function returns
+	* to it. Return value should be smaller than 0 if value a is smaller
+	* than value b. This has been reversed in the comparision function in
+	* order to sort the guessers from high to low.
+	* Method has been set to public in order to allow proper testing.
+	*
+	* @param object $guesser_a Mimetype guesser a
+	* @param object $guesser_b Mimetype guesser b
+	*
+	* @return int 	If both guessers have the same priority 0, bigger
+	*		than 0 if first guesser has lower priority, and lower
+	*		than 0 if first guesser has higher priority
+	*/
+	public function sort_priority($guesser_a, $guesser_b)
+	{
+		$priority_a = (int) (method_exists($guesser_a, 'get_priority')) ? $guesser_a->get_priority() : self::PRIORITY_DEFAULT;
+		$priority_b = (int) (method_exists($guesser_b, 'get_priority')) ? $guesser_b->get_priority() : self::PRIORITY_DEFAULT;
+
+		return $priority_b - $priority_a;
 	}
 
 	/**
diff --git a/phpBB/phpbb/mimetype/guesser_base.php b/phpBB/phpbb/mimetype/guesser_base.php
new file mode 100644
index 0000000000..b35badea54
--- /dev/null
+++ b/phpBB/phpbb/mimetype/guesser_base.php
@@ -0,0 +1,46 @@
+<?php
+/**
+*
+* @package phpBB3
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+namespace phpbb\mimetype;
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* @package mimetype
+*/
+
+abstract class guesser_base implements guesser_interface
+{
+	/**
+	* @var int Guesser Priority
+	*/
+	protected $priority;
+
+	/**
+	* @inheritdoc
+	*/
+	public function get_priority()
+	{
+		return $this->priority;
+	}
+
+	/**
+	* @inheritdoc
+	*/
+	public function set_priority($priority)
+	{
+		$this->priority = $priority;
+	}
+}
diff --git a/phpBB/phpbb/mimetype/guesser_interface.php b/phpBB/phpbb/mimetype/guesser_interface.php
index a9b238d7aa..defff90654 100644
--- a/phpBB/phpbb/mimetype/guesser_interface.php
+++ b/phpBB/phpbb/mimetype/guesser_interface.php
@@ -38,4 +38,20 @@ interface guesser_interface
 	* @return string Guess for mimetype of file
 	*/
 	public function guess($file, $file_name = '');
+
+	/**
+	* Get the guesser priority
+	*
+	* @return int Guesser priority
+	*/
+	public function get_priority();
+
+	/**
+	* Set the guesser priority
+	*
+	* @param int Guesser priority
+	*
+	* @return void
+	*/
+	public function set_priority($priority);
 }