minor symfony#7358 [File Uploads] Check if the entity contains the files (Guikingone)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes symfony#7358).

Discussion
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[File Uploads] Check if the entity contains the files

After many tests, it seems that if the entity does not contains the files, the event throw a Exception, by checking the presence of files, the exception isn't thrown and the process can continue, this can be usefull if the entity isn't linked with file or if the file was stored into an array but not needed at this time.

The return isn't needed after the if statement.

Commits
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cc0d418 [File Uploads] Check if the entity contains the files

Author: xabbuh

controller/upload_file.rst

@@ -456,9 +456,9 @@ controller.
                     return;
                 }
 
-                $fileName = $entity->getBrochure();
-
-                $entity->setBrochure(new File($this->uploader->getTargetDir().'/'.$fileName));
+                if ($fileName = $entity->getBrochure()) {
+                    $entity->setBrochure(new File($this->uploader->getTargetDir().'/'.$fileName));
+                }
             }
         }