Avoid chmoding unless requested, fixes #348

src/Monolog/Handler/StreamHandler.php

@@ -33,7 +33,7 @@ class StreamHandler extends AbstractProcessingHandler
      * @param Boolean $bubble          Whether the messages that are handled can bubble up the stack or not
      * @param int     $filePermissions Optional file permissions (default (0644) are only for owner read/write)
      */
-    public function __construct($stream, $level = Logger::DEBUG, $bubble = true, $filePermission = 0644)
+    public function __construct($stream, $level = Logger::DEBUG, $bubble = true, $filePermission = null)
     {
         parent::__construct($level, $bubble);
         if (is_resource($stream)) {
@@ -68,7 +68,9 @@ class StreamHandler extends AbstractProcessingHandler
             $this->errorMessage = null;
             set_error_handler(array($this, 'customErrorHandler'));
             $this->stream = fopen($this->url, 'a');
-            @chmod($this->url, $this->filePermission);
+            if ($this->filePermission !== null) {
+                @chmod($this->url, $this->filePermission);
+            }
             restore_error_handler();
             if (!is_resource($this->stream)) {
                 $this->stream = null;