merged branch tystr/sanitize_queries_fix (PR #3032)

Commits
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261325d Cast $query['params'] to array to ensure it is a valid argument for the foreach.

Discussion
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[DoctrineBridge] Account for $query['params'] being null in DoctrineDataCollector's sanitizeQueries method

I was getting this error because inside the sanitizeQueries method of DoctrineDataCollector, there's no handling for $query['params'] being null.

ErrorException: Warning: Invalid argument supplied for foreach() in .../vendor/symfony/src/Symfony/Bridge/Doctrine/DataCollector/DoctrineDataCollector.php line 91

src/Symfony/Bridge/Doctrine/DataCollector/DoctrineDataCollector.php

@@ -88,7 +88,7 @@ class DoctrineDataCollector extends DataCollector
     private function sanitizeQueries($queries)
     {
         foreach ($queries as $i => $query) {
-            foreach ($query['params'] as $j => $param) {
+            foreach ((array)$query['params'] as $j => $param) {
                 $queries[$i]['params'][$j] = $this->varToString($param);
             }
         }