minor symfony#23835 [HttpFoundation] Remove length limit on ETag (nicolas-grekas)

This PR was merged into the 3.4 branch.

Discussion
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[HttpFoundation] Remove length limit on ETag

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#23766 (comment)
| License       | MIT
| Doc PR        | -

Commits
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e6406d2 [HttpFoundation] Remove length limit on ETag

Author: fabpot

src/Symfony/Component/HttpFoundation/BinaryFileResponse.php

@@ -141,7 +141,7 @@ public function setAutoLastModified()
      */
     public function setAutoEtag()
     {
-        $this->setEtag(substr(base64_encode(hash_file('sha256', $this->file->getPathname(), true)), 0, 32));
+        $this->setEtag(base64_encode(hash_file('sha256', $this->file->getPathname(), true)));
 
         return $this;
     }