Fix Endless loop

Fix

src/ChunkedDecoder.php

@@ -95,21 +95,21 @@ public function handleData($data)
                     return;
                 }
 
-                $hexValue = strtolower(substr($this->buffer, 0, $positionClrf));
+                $hexValue = strtolower((string)substr($this->buffer, 0, $positionClrf));
                 if (dechex(hexdec($hexValue)) !== $hexValue || hexdec($hexValue) > 2147483647) {
                     $this->handleError(new \Exception($hexValue . ' is not a hexadecimal number or too big'));
                     return;
                 }
 
                 $this->chunkSize = hexdec($hexValue);
-                $this->buffer = substr($this->buffer, strlen($hexValue) + 2);
+                $this->buffer = (string)substr($this->buffer, strlen($hexValue) + 2);
                 $this->headerCompleted = true;
                 if ($this->buffer === '') {
                     return;
                 }
             }
 
-            $chunk = substr($this->buffer, 0, $this->chunkSize - $this->transferredSize);
+            $chunk = (string)substr($this->buffer, 0, $this->chunkSize - $this->transferredSize);
             if ($chunk !== '') {
                 $this->transferredSize += strlen($chunk);
                 if ($this->transferredSize > $this->chunkSize) {
@@ -118,7 +118,7 @@ public function handleData($data)
                 }
 
                 $this->emit('data', array($chunk));
-                $this->buffer = substr($this->buffer, strlen($chunk));
+                $this->buffer = (string)substr($this->buffer, strlen($chunk));
             }
 
             if (strpos($this->buffer, static::CRLF) !== false) {
@@ -132,7 +132,7 @@ public function handleData($data)
                 $this->chunkSize = 0;
                 $this->headerCompleted = false;
                 $this->transferredSize = 0;
-                $this->buffer = substr($this->buffer, 2);
+                $this->buffer = (string)substr($this->buffer, 2);
             }
         }
     }