Merge branch '5.1' into 5.x

* 5.1:
  [DI] fix dumping env vars
  [HttpClient] skip executing the multi handle when it's freed already
  [HttpClient] fix using freed curl resource at destruct time
  [HttpClient] shutdown verbose output from curl at destruction
  fix warning for preloading TranslatorTrait class
  [Typography] Remove unneeded description comments

Author: nicolas-grekas

CurlHttpClient.php

@@ -331,8 +331,10 @@ public function stream($responses, float $timeout = null): ResponseStreamInterfa
             throw new \TypeError(sprintf('"%s()" expects parameter 1 to be an iterable of CurlResponse objects, "%s" given.', __METHOD__, get_debug_type($responses)));
         }
 
-        $active = 0;
-        while (\CURLM_CALL_MULTI_PERFORM === curl_multi_exec($this->multi->handle, $active));
+        if (\is_resource($this->multi->handle) || $this->multi->handle instanceof \CurlMultiHandle) {
+            $active = 0;
+            while (\CURLM_CALL_MULTI_PERFORM === curl_multi_exec($this->multi->handle, $active));
+        }
 
         return new ResponseStream(CurlResponse::stream($responses, $timeout));
     }

Response/CurlResponse.php

@@ -247,6 +247,8 @@ public function getContent(bool $throw = true): string
 
     public function __destruct()
     {
+        curl_setopt($this->handle, \CURLOPT_VERBOSE, false);
+
         if (null === $this->timeout) {
             return; // Unused pushed response
         }