diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index ee5a1afd30..9c92adb0ec 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -4940,6 +4940,20 @@ function phpbb_quoteattr($data, $entities = null)
 	return $data;
 }
 
+/**
+* Converts query string (GET) parameters in request into hidden fields.
+*
+* Useful for forwarding GET parameters when submitting forms with GET method.
+*
+* It is possible to omit some of the GET parameters, which is useful if
+* they are specified in the form being submitted.
+*
+* sid is always omitted.
+*
+* @param phpbb_request $request Request object
+* @param array $exclude A list of variable names that should not be forwarded
+* @return string HTML with hidden fields
+*/
 function phpbb_build_hidden_fields_for_query_params($request, $exclude = null)
 {
 	$names = $request->variable_names(phpbb_request_interface::GET);
diff --git a/tests/functions/build_hidden_fields_for_query_params_test.php b/tests/functions/build_hidden_fields_for_query_params_test.php
new file mode 100644
index 0000000000..ef2f5744d3
--- /dev/null
+++ b/tests/functions/build_hidden_fields_for_query_params_test.php
@@ -0,0 +1,71 @@
+<?php
+/**
+*
+* @package testing
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+require_once dirname(__FILE__) . '/../../phpBB/includes/functions.php';
+
+class phpbb_build_hidden_fields_for_query_params_test extends phpbb_test_case
+{
+	public function build_hidden_fields_for_query_params_test_data()
+	{
+		return array(
+			// get
+			// post
+			// exclude
+			// expected
+			array(
+				array('foo' => 'bar'),
+				array(),
+				array(),
+				"<input type='hidden' name=\"foo\" value=\"bar\" />",
+			),
+			array(
+				array('foo' => 'bar', 'a' => 'b'),
+				array(),
+				array(),
+				"<input type='hidden' name=\"foo\" value=\"bar\" /><input type='hidden' name=\"a\" value=\"b\" />",
+			),
+			array(
+				array('a' => 'quote"', 'b' => '<less>'),
+				array(),
+				array(),
+				"<input type='hidden' name=\"a\" value='quote\"' /><input type='hidden' name=\"b\" value=\"&lt;less&gt;\" />",
+			),
+			array(
+				array('a' => "quotes'\""),
+				array(),
+				array(),
+				"<input type='hidden' name=\"a\" value=\"quotes'&quot;\" />",
+			),
+			array(
+				array('foo' => 'bar', 'a' => 'b'),
+				array('a' => 'c'),
+				array(),
+				"<input type='hidden' name=\"foo\" value=\"bar\" />",
+			),
+			// strict equality check
+			array(
+				array('foo' => 'bar', 'a' => '0'),
+				array('a' => ''),
+				array(),
+				"<input type='hidden' name=\"foo\" value=\"bar\" />",
+			),
+		);
+	}
+
+	/**
+	* @dataProvider build_hidden_fields_for_query_params_test_data
+	*/
+	public function test_build_hidden_fields_for_query_params($get, $post, $exclude, $expected)
+	{
+		$request = new phpbb_mock_request($get, $post);
+		$result = phpbb_build_hidden_fields_for_query_params($request, $exclude);
+
+		$this->assertEquals($expected, $result);
+	}
+}