Merge branch '3.x' into 4.x

* 3.x:
  Fix the null coalescing operator when the test returns null
  Fix the Elvis operator when there is some space between ? and :
  Bump version
  Prepare the 3.17.0 release
  Update CHANGELOG

src/Extension/CoreExtension.php

@@ -324,6 +324,7 @@ final class CoreExtension extends AbstractExtension
                 '+' => ['precedence' => 500, 'class' => PosUnary::class],
             ],
             [
+                '? :' => ['precedence' => 5, 'class' => ElvisBinary::class, 'associativity' => ExpressionParser::OPERATOR_RIGHT],
                 '?:' => ['precedence' => 5, 'class' => ElvisBinary::class, 'associativity' => ExpressionParser::OPERATOR_RIGHT],
                 '??' => ['precedence' => 5, 'class' => NullCoalesceBinary::class, 'associativity' => ExpressionParser::OPERATOR_RIGHT],
                 'or' => ['precedence' => 10, 'class' => OrBinary::class, 'associativity' => ExpressionParser::OPERATOR_LEFT],

src/Node/Expression/Binary/NullCoalesceBinary.php

@@ -29,8 +29,7 @@ final class NullCoalesceBinary extends AbstractBinary implements OperatorEscapeI
         parent::__construct($left, $right, $lineno);
 
         if (!$left instanceof ContextVariable) {
-            $left = clone $left;
-            $test = new DefinedTest($left, new TwigTest('defined'), new EmptyNode(), $left->getTemplateLine());
+            $test = new DefinedTest(clone $left, new TwigTest('defined'), new EmptyNode(), $left->getTemplateLine());
             // for "block()", we don't need the null test as the return value is always a string
             if (!$left instanceof BlockReferenceExpression) {
                 $test = new AndBinary(

tests/Fixtures/expressions/ternary_operator_nothen.test

@@ -3,8 +3,16 @@ Twig supports the ternary operator
 --TEMPLATE--
 {{ 'YES' ?: 'NO' }}
 {{ 0 ?: 'NO' }}
+{{ 'YES' ? : 'NO' }}
+{{ 0 ? : 'NO' }}
+{{ 'YES' ?  : 'NO' }}
+{{ 0 ?     : 'NO' }}
 --DATA--
 return []
 --EXPECT--
 YES
 NO
+YES
+NO
+YES
+NO

tests/Fixtures/tests/null_coalesce.test

@@ -14,8 +14,10 @@ Twig supports the ?? operator
 {{ 1 + (nope ?? (nada ?? 2)) }}
 {{ 1 + (nope ?? 3) + (nada ?? 2) }}
 {{ nope ?? nada ?? 2 }}
+{{ obj.null() ?? 'OK' }}
+{{ obj.empty() ?? 'KO' }}
 --DATA--
-return ['bar' => 'OK', 'foo' => ['bar' => 'OK']]
+return ['bar' => 'OK', 'foo' => ['bar' => 'OK'], 'obj' => new Twig\Tests\TwigTestFoo()]
 --EXPECT--
 OK
 OK
@@ -29,4 +31,5 @@ OK
 OK
 3
 6
-2
+2
+OK

tests/IntegrationTest.php

@@ -77,6 +77,16 @@ class TwigTestFoo implements \Iterator
         return 'foo';
     }
 
+    public function getEmpty()
+    {
+        return '';
+    }
+
+    public function getNull()
+    {
+        return null;
+    }
+
     public function getSelf()
     {
         return $this;