Fix warning when calling hasVariable for an undefined variable (#978)

Fixes #977

changelog/977.md

@@ -0,0 +1 @@
+- Fix warning when calling hasVariable for an undefined variable [#977](https://github.com/smarty-php/smarty/issues/977)

src/Data.php

@@ -290,7 +290,7 @@ public function setVariable($varName, Variable $variableObject) {
 	 * @return bool
 	 */
 	public function hasVariable($varName): bool {
-		return !($this->getVariable($varName) instanceof UndefinedVariable);
+		return !($this->getVariable($varName, true, false) instanceof UndefinedVariable);
 	}
 
 	/**

tests/UnitTests/SmartyMethodsTests/TemplateVars/HasVariableTest.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Tests the ::hasVariable method
+ */
+class HasVariableTest extends PHPUnit_Smarty
+{
+	public function setUp(): void
+	{
+		$this->setUpSmarty(__DIR__);
+	}
+
+
+	public function testInit()
+	{
+		$this->cleanDirs();
+	}
+
+	public function testSimpleTrue()
+	{
+		$this->smarty->assign('foo', 'bar');
+		$this->assertTrue($this->smarty->hasVariable('foo'));
+	}
+
+
+	public function testSimpleFalse()
+	{
+		$this->smarty->assign('foo', 'bar');
+		$this->assertFalse($this->smarty->hasVariable('foox'));
+	}
+
+}