[HttpKernel] Fix datacollector caster for reference object property

[ebuildy]

Q	A
Branch?	5.4
Bug fix?	yes
New feature?	no
Deprecations?	no
Issues	Fix #49091
License	MIT

As discussed on #49091:

• fix story "when assigning a variable reference to a public object property"
• add test for story "use object property in destruct method" (relate to fix hookdatacollector clone smarty component PrestaShop/PrestaShop#35466 )

Unit tests FAIL "Error: KO src/Symfony/Component/HttpKernel" --> normal

[nicolas-grekas]

Nice, thanks for the test cases.
Here is the correct patch that fixes both aspect of the issue:

--- a/src/Symfony/Component/HttpKernel/DataCollector/DataCollector.php
+++ b/src/Symfony/Component/HttpKernel/DataCollector/DataCollector.php
@@ -70,16 +70,21 @@ abstract class DataCollector implements DataCollectorInterface
         $casters = [
             '*' => function ($v, array $a, Stub $s, $isNested) {
                 if (!$v instanceof Stub) {
+                    $b = $a;
                     foreach ($a as $k => $v) {
                         if (!\is_object($v) || $v instanceof \DateTimeInterface || $v instanceof Stub) {
                             continue;
                         }
 
                         try {
-                            $a[$k] = new CutStub($v);
+                            $a[$k] = $s = new CutStub($v);
+
+                            if ($b[$k] === $s) {
+                                // we've hit a non-typed reference
+                                $a[$k] = $v;
+                            }
                         } catch (\TypeError $e) {
-                            $a[$k] = &$v;
-                            unset($v);
+                            // we've hit a typed reference
                         }
                     }
                 }

[nicolas-grekas]

Can you please make the necessary changes to fix the CI on PHP 7.2+? (that could involve using @requires PHP 8.0 on test cases of course)

[nicolas-grekas]

Thank you @ebuildy.