Merge branch '3.3' into 3.4

* 3.3:
  removed extra whitespace
  Removes \n or space when / are empty
  [HttpFoundation] add Early Hints in Reponse to fix test
  Throwing exception if redis and predis unavailable

Author: fabpot

src/Symfony/Bridge/Monolog/Formatter/ConsoleFormatter.php

@@ -117,12 +117,20 @@ public function format(array $record)
         $levelColor = self::$levelColorMap[$record['level']];
 
         if ($this->options['multiline']) {
-            $context = $extra = "\n";
+            $separator = "\n";
         } else {
-            $context = $extra = ' ';
+            $separator = ' ';
+        }
+
+        $context = $this->dumpData($record['context']);
+        if ($context) {
+            $context = $separator.$context;
+        }
+
+        $extra = $this->dumpData($record['extra']);
+        if ($extra) {
+            $extra = $separator.$extra;
         }
-        $context .= $this->dumpData($record['context']);
-        $extra .= $this->dumpData($record['extra']);
 
         $formatted = strtr($this->options['format'], array(
             '%datetime%' => $record['datetime']->format($this->options['date_format']),

src/Symfony/Component/Cache/Traits/RedisTrait.php

@@ -16,6 +16,7 @@
 use Predis\Connection\Aggregate\PredisCluster;
 use Predis\Connection\Aggregate\RedisCluster;
 use Predis\Response\Status;
+use Symfony\Component\Cache\Exception\CacheException;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 
 /**
@@ -108,6 +109,9 @@ public static function createConnection($dsn, array $options = array())
             $params += $query;
         }
         $params += $options + self::$defaultConnectionOptions;
+        if (null === $params['class'] && !extension_loaded('redis') && !class_exists(\Predis\Client::class)) {
+            throw new CacheException(sprintf('Cannot find the "redis" extension, and "predis/predis" is not installed: %s', $dsn));
+        }
         $class = null === $params['class'] ? (extension_loaded('redis') ? \Redis::class : \Predis\Client::class) : $params['class'];
 
         if (is_a($class, \Redis::class, true)) {

src/Symfony/Component/HttpFoundation/Response.php

@@ -126,6 +126,7 @@ class Response
         100 => 'Continue',
         101 => 'Switching Protocols',
         102 => 'Processing',            // RFC2518
+        103 => 'Early Hints',
         200 => 'OK',
         201 => 'Created',
         202 => 'Accepted',