bug symfony#25119 [DI] Fix infinite loop when analyzing references (nicolas-grekas)

This PR was merged into the 3.4 branch.

Discussion
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[DI] Fix infinite loop when analyzing references

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#25101
| License       | MIT
| Doc PR        | -

Commits
-------

f772d2f [DI] Fix infinite loop when analyzing references

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php

@@ -356,6 +356,7 @@ private function analyzeCircularReferences(array $edges, &$checkedNodes, &$curre
             if (isset($checkedNodes[$id])) {
                 continue;
             }
+            $checkedNodes[$id] = true;
 
             if ($node->getValue() && ($edge->isLazy() || $edge->isWeak())) {
                 // no-op
@@ -367,10 +368,8 @@ private function analyzeCircularReferences(array $edges, &$checkedNodes, &$curre
             } else {
                 $currentPath[$id] = $id;
                 $this->analyzeCircularReferences($node->getOutEdges(), $checkedNodes, $currentPath);
+                array_pop($currentPath);
             }
-
-            $checkedNodes[$id] = true;
-            array_pop($currentPath);
         }
     }