Merge branch 'master' into fix_4258

Conflicts:
	lib/image.php

diff --cc lib/image.php
index fcb13a1fa14998df16e191b394087af184e2e0d0,840b744ad723f8f4036f955e279b3f2e04f15f22..badc30ab9a04a19f90e710ab7ea4f0653204586f
--- 1/lib/image.php
--- 2/lib/image.php
+++ b/lib/image.php
@@@ -519,9 -496,11 +519,14 @@@ class OC_Image 
                        return false;
                }
                $this->resource = @imagecreatefromstring($str);
 +              if (\OC_Util::fileInfoLoaded()) {
 +                      $this->mimeType = $this->fileInfo->buffer($str);
 +              }
+               if(is_resource($this->resource)) {
+                       imagealphablending($this->resource, false);
+                       imagesavealpha($this->resource, true);
+               }
+ 
                if(!$this->resource) {
                        OC_Log::write('core', 'OC_Image->loadFromData, couldn\'t load', OC_Log::DEBUG);
                        return false;