Added some unit test to study consistent behavior on passing argument…

… by reference.

tests/UnitTests/TemplateSource/_Issues/ArgumentMustBePassedByReference961Test.php

@@ -0,0 +1,65 @@
+<?php
+
+class ArgumentMustBePassedByReference961Test extends PHPUnit_Smarty
+{
+
+	/**
+	 * @group issue961
+	 */
+	public function testReset()
+	{
+		$smarty = new Smarty();
+		$smarty->registerPlugin('modifier', 'reset', 'reset');
+		$templateStr = "string:{reset(\$ar)}";
+		$smarty->assign('ar', [1,2,3]);
+		$this->assertEquals(
+			'1',
+			$smarty->fetch($templateStr)
+		);
+	}
+
+	/**
+	 * @group issue961
+	 */
+	public function testResetAsModifier()
+	{
+		$smarty = new Smarty();
+		$templateStr = "string:{\$ar|reset}";
+		$smarty->assign('ar', [1,2,3]);
+		$this->assertEquals(
+			'1',
+			$smarty->fetch($templateStr)
+		);
+	}
+
+	/**
+	 * @group issue961
+	 */
+	public function testResetInExpression()
+	{
+		$smarty = new Smarty();
+		$smarty->registerPlugin('modifier', 'reset', 'reset');
+		$templateStr = "string:{if reset(\$ar)}ok{/if}";
+		$smarty->assign('ar', [1,2,3]);
+		$this->assertEquals(
+			'ok',
+			$smarty->fetch($templateStr)
+		);
+	}
+
+	/**
+	 * @group issue961
+	 * @deprecated
+	 */
+	public function testMatch()
+	{
+		$smarty = new Smarty();
+		$smarty->setErrorReporting(E_ALL & ~ E_USER_DEPRECATED);
+		$smarty->registerPlugin('modifier', 'preg_match', 'preg_match');
+		$templateStr = 'string:{assign var="match" value=null}{if preg_match(\'/([a-z]{4})/\', "a test", $match)}{$match.1}{/if}';
+		$this->assertEquals(
+			'test',
+			$smarty->fetch($templateStr)
+		);
+	}
+}