bug #13351 [VarDumper] fix very special vars handling (nicolas-grekas)

This PR was merged into the 2.6 branch.

Discussion
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[VarDumper] fix very special vars handling

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #13235
| License       | MIT
| Doc PR        | -

Commits
-------

e26dc2c [VarDumper] fix very special vars handling

Author: fabpot

Tests/DataCollector/DumpDataCollectorTest.php

@@ -50,7 +50,7 @@ public function testDump()
         $this->assertSame($xDump, $dump);
 
         $this->assertStringStartsWith(
-            'a:1:{i:0;a:5:{s:4:"data";O:39:"Symfony\Component\VarDumper\Cloner\Data":4:{s:45:"Symfony\Component\VarDumper\Cloner\Datadata";a:1:{i:0;a:1:{i:0;i:123;}}s:49:"Symfony\Component\VarDumper\Cloner\DatamaxDepth";i:-1;s:57:"Symfony\Component\VarDumper\Cloner\DatamaxItemsPerDepth";i:-1;s:54:"Symfony\Component\VarDumper\Cloner\DatauseRefHandles";i:-1;}s:4:"name";s:25:"DumpDataCollectorTest.php";s:4:"file";s:',
+            'a:1:{i:0;a:5:{s:4:"data";O:39:"Symfony\Component\VarDumper\Cloner\Data":4:{s:45:"Symfony\Component\VarDumper\Cloner\Datadata";a:1:{i:0;a:1:{i:0;i:123;}}s:49:"Symfony\Component\VarDumper\Cloner\DatamaxDepth";i:20;s:57:"Symfony\Component\VarDumper\Cloner\DatamaxItemsPerDepth";i:-1;s:54:"Symfony\Component\VarDumper\Cloner\DatauseRefHandles";i:-1;}s:4:"name";s:25:"DumpDataCollectorTest.php";s:4:"file";s:',
             str_replace("\0", '', $collector->serialize())
         );