[!!!][BUGFIX] Cast negative int to boolean (true) in BooleanNode

Currently Fluid treats negative integers as false which
results in <f:if condition="-9"> rendering else instead
of then.

When casting integers to boolean using php all integers
other than 0 (zero) are casted to true, just 0 results in
false. Therefore, casting of BooleanNode::convertToBoolean
must be adjusted to act like plain php.

This bugfix is a breaking change as people might have
deliberately used the wrong behaviour.

Releases: 6.2
Resolves: #54243
Resolves: #33597
Change-Id: Iebaa578cf071909610ca0e1abfc9bfaad7459231
Reviewed-on: https://review.typo3.org/26784
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader
Reviewed-by: Stefan Neufeind
Reviewed-by: Nicole Cordes
Tested-by: Nicole Cordes

typo3/sysext/fluid/Classes/Core/Parser/SyntaxTree/BooleanNode.php

@@ -318,18 +318,25 @@ class BooleanNode extends \TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\AbstractNode {
 		if (is_bool($value)) {
 			return $value;
 		}
+
+		if (is_integer($value) || is_float($value)) {
+			return !empty($value);
+		}
+
 		if (is_numeric($value)) {
-			return $value > 0;
+			return ($value != 0);
 		}
+
 		if (is_string($value)) {
 			return (!empty($value) && strtolower($value) !== 'false');
 		}
 		if (is_array($value) || (is_object($value) && $value instanceof \Countable)) {
-			return count($value) > 0;
+			return (bool) count($value);
 		}
 		if (is_object($value)) {
 			return TRUE;
 		}
+
 		return FALSE;
 	}
 }

typo3/sysext/fluid/Tests/Unit/Core/Parser/SyntaxTree/BooleanNodeTest.php

@@ -409,13 +409,41 @@ class BooleanNodeTest extends \TYPO3\CMS\Core\Tests\UnitTestCase {
 	 * @test
 	 */
 	public function convertToBooleanProperlyConvertsNumericValues() {
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(FALSE));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(TRUE));
+
 		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0));
-		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(-1));
-		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('-1'));
-		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(-0.5));
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0'));
+
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0.0));
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0.0'));
+
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0x0));
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0x0'));
+
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0x1));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0x1'));
+
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0e0));
+		$this->assertFalse(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0e0'));
+
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(1e0));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('1e0'));
+
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(-1));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('-1'));
+
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(-0.5));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('-0.5'));
 
 		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(1));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('1'));
+
 		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0.5));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0.5'));
+
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean(0x1));
+		$this->assertTrue(\TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\BooleanNode::convertToBoolean('0x10'));
 	}
 
 	/**