bug #4841 Fix Markup truthiness in boolean expressions (xtrime-ru)

This PR was merged into the 3.x branch.

Discussion
----------

Fix Markup truthiness in boolean expressions

## Summary

Fixes Markup truthiness handling in boolean expressions.

`trim` can return a `Twig\Markup` instance for safe strings. Empty `Markup` objects must behave like empty strings in Twig truth tests, but PHP treats all objects as truthy. This caused expressions like this to incorrectly evaluate as true:
```twig
{% set x %}    {% endset %}
{% if x|trim and x|trim %}fail{% else %}ok{% endif %}
```

This case was working properly in https://github.com/twigphp/Twig/releases/tag/v3.14.2 and earlier.

## Related commits
- Bug was introduced in [v3.15.0](https://github.com/twigphp/Twig/releases/tag/v3.15.0) in this commit https://github.com/twigphp/Twig/commit/10c3142d3b036910f63080070c101bfff61e0743
- Partially fixed here:  https://github.com/twigphp/Twig/commit/10c3142d3b036910f63080070c101bfff61e0743

## Changes

- Added `TrueTest::wrap()` to centralize wrapping non-primitive expressions with Twig’s Markup-aware true test.
- Reused `TrueTest::wrap()` in:
  - `IfNode`
  - conditional ternary expressions
  - `and`, `or`, and `xor` binary expressions
  - Elvis expressions
  - unary `not`
- Added regression coverage for boolean operators (`and`, `or`, `xor`, `not`) and ternary/Elvis expressions whose operands evaluate to empty `Markup`.

## Tests
```bash
./vendor/bin/simple-phpunit tests/IntegrationTest.php --filter markup_test
```

Commits
-------

f5afaabf54 Fix Markup truthiness in boolean expressions

src/Node/Expression/Binary/AndBinary.php

@@ -14,9 +14,16 @@ namespace Twig\Node\Expression\Binary;
 
 use Twig\Compiler;
 use Twig\Node\Expression\ReturnBoolInterface;
+use Twig\Node\Expression\Test\TrueTest;
+use Twig\Node\Node;
 
 class AndBinary extends AbstractBinary implements ReturnBoolInterface
 {
+    public function __construct(Node $left, Node $right, int $lineno)
+    {
+        parent::__construct(TrueTest::wrap($left), TrueTest::wrap($right), $lineno);
+    }
+
     public function operator(Compiler $compiler): Compiler
     {
         return $compiler->raw('&&');

src/Node/Expression/Binary/ElvisBinary.php

@@ -14,6 +14,7 @@ namespace Twig\Node\Expression\Binary;
 use Twig\Compiler;
 use Twig\Node\Expression\AbstractExpression;
 use Twig\Node\Expression\OperatorEscapeInterface;
+use Twig\Node\Expression\Test\TrueTest;
 use Twig\Node\Node;
 
 final class ElvisBinary extends AbstractBinary implements OperatorEscapeInterface
@@ -26,7 +27,7 @@ final class ElvisBinary extends AbstractBinary implements OperatorEscapeInterfac
     {
         parent::__construct($left, $right, $lineno);
 
-        $this->setNode('test', clone $left);
+        $this->setNode('test', TrueTest::wrap(clone $left));
         $left->setAttribute('always_defined', true);
     }
 

src/Node/Expression/Binary/OrBinary.php

@@ -14,9 +14,16 @@ namespace Twig\Node\Expression\Binary;
 
 use Twig\Compiler;
 use Twig\Node\Expression\ReturnBoolInterface;
+use Twig\Node\Expression\Test\TrueTest;
+use Twig\Node\Node;
 
 class OrBinary extends AbstractBinary implements ReturnBoolInterface
 {
+    public function __construct(Node $left, Node $right, int $lineno)
+    {
+        parent::__construct(TrueTest::wrap($left), TrueTest::wrap($right), $lineno);
+    }
+
     public function operator(Compiler $compiler): Compiler
     {
         return $compiler->raw('||');

src/Node/Expression/Binary/XorBinary.php

@@ -14,9 +14,16 @@ namespace Twig\Node\Expression\Binary;
 
 use Twig\Compiler;
 use Twig\Node\Expression\ReturnBoolInterface;
+use Twig\Node\Expression\Test\TrueTest;
+use Twig\Node\Node;
 
 class XorBinary extends AbstractBinary implements ReturnBoolInterface
 {
+    public function __construct(Node $left, Node $right, int $lineno)
+    {
+        parent::__construct(TrueTest::wrap($left), TrueTest::wrap($right), $lineno);
+    }
+
     public function operator(Compiler $compiler): Compiler
     {
         return $compiler->raw('xor');

src/Node/Expression/Ternary/ConditionalTernary.php

@@ -14,19 +14,13 @@ namespace Twig\Node\Expression\Ternary;
 use Twig\Compiler;
 use Twig\Node\Expression\AbstractExpression;
 use Twig\Node\Expression\OperatorEscapeInterface;
-use Twig\Node\Expression\ReturnPrimitiveTypeInterface;
 use Twig\Node\Expression\Test\TrueTest;
-use Twig\TwigTest;
 
 final class ConditionalTernary extends AbstractExpression implements OperatorEscapeInterface
 {
     public function __construct(AbstractExpression $test, AbstractExpression $left, AbstractExpression $right, int $lineno)
     {
-        if (!$test instanceof ReturnPrimitiveTypeInterface) {
+        parent::__construct(['test' => TrueTest::wrap($test), 'left' => $left, 'right' => $right], [], $lineno);
-            $test = new TrueTest($test, new TwigTest('true', null, ['always_allowed_in_sandbox' => true]), null, $test->getTemplateLine());
-        }
-
-        parent::__construct(['test' => $test, 'left' => $left, 'right' => $right], [], $lineno);
     }
 
     public function compile(Compiler $compiler): void

src/Node/Expression/Test/TrueTest.php

@@ -12,7 +12,10 @@
 namespace Twig\Node\Expression\Test;
 
 use Twig\Compiler;
+use Twig\Node\Expression\ReturnPrimitiveTypeInterface;
 use Twig\Node\Expression\TestExpression;
+use Twig\Node\Node;
+use Twig\TwigTest;
 
 /**
  * Checks that an expression is true.
@@ -23,6 +26,15 @@ use Twig\Node\Expression\TestExpression;
  */
 class TrueTest extends TestExpression
 {
+    public static function wrap(Node $node): Node
+    {
+        if ($node instanceof ReturnPrimitiveTypeInterface) {
+            return $node;
+        }
+
+        return new self($node, new TwigTest('true', null, ['always_allowed_in_sandbox' => true]), null, $node->getTemplateLine());
+    }
+
     public function compile(Compiler $compiler): void
     {
         $compiler

src/Node/Expression/Unary/NotUnary.php

@@ -13,9 +13,17 @@
 namespace Twig\Node\Expression\Unary;
 
 use Twig\Compiler;
+use Twig\Node\Expression\ReturnBoolInterface;
+use Twig\Node\Expression\Test\TrueTest;
+use Twig\Node\Node;
 
-class NotUnary extends AbstractUnary
+class NotUnary extends AbstractUnary implements ReturnBoolInterface
 {
+    public function __construct(Node $node, int $lineno)
+    {
+        parent::__construct(TrueTest::wrap($node), $lineno);
+    }
+
     public function operator(Compiler $compiler): Compiler
     {
         return $compiler->raw('!');

src/Node/IfNode.php

@@ -14,9 +14,7 @@ namespace Twig\Node;
 
 use Twig\Attribute\YieldReady;
 use Twig\Compiler;
-use Twig\Node\Expression\ReturnPrimitiveTypeInterface;
 use Twig\Node\Expression\Test\TrueTest;
-use Twig\TwigTest;
 
 /**
  * Represents an if node.
@@ -29,10 +27,7 @@ class IfNode extends Node
     public function __construct(Node $tests, ?Node $else, int $lineno)
     {
         for ($i = 0, $count = \count($tests); $i < $count; $i += 2) {
-            $test = $tests->getNode((string) $i);
+            $tests->setNode($i, TrueTest::wrap($tests->getNode((string) $i)));
-            if (!$test instanceof ReturnPrimitiveTypeInterface) {
-                $tests->setNode($i, new TrueTest($test, new TwigTest('true', null, ['always_allowed_in_sandbox' => true]), null, $test->getTemplateLine()));
-            }
         }
         $nodes = ['tests' => $tests];
         if (null !== $else) {

tests/Fixtures/regression/markup_test.test

@@ -8,6 +8,14 @@ Twig outputs 0 nodes correctly
 {% if spaces|trim %}KO{% else %}ok{% endif %}
 
 {% set bar %}    {% endset %}{{ bar|trim ? 'KO' : 'ok' }}
+{% if bar|trim and bar|trim %}KO{% else %}ok{% endif %}{{- "\n" -}}
+{% if bar|trim or empty|trim %}KO{% else %}ok{% endif %}{{- "\n" -}}
+{% if bar|trim xor empty|trim %}KO{% else %}ok{% endif %}{{- "\n" -}}
+{% if not bar|trim %}ok{% else %}KO{% endif %}{{- "\n" -}}
+{{ bar|trim ?: 'ok' }}
+{{ (bar|trim and bar|trim) ? 'KO' : 'ok' }}
+{{ (bar|trim and bar|trim) ?: 'ok' }}
+{{ (bar|trim and bar|trim) ?: (bar|trim ?: 'ok') }}
 --DATA--
 return ['spaces' => new Twig\Markup('    ', 'UTF-8'), 'empty' => new Twig\Markup('', 'UTF-8')]
 --EXPECT--
@@ -16,3 +24,11 @@ ok
 ok
 ok
 ok
+ok
+ok
+ok
+ok
+ok
+ok
+ok
+ok