title: Rails application using Rmagick, function from_blob fails with NoDecodeDelegateForThisImageFormat after ImageMagick update
body: <p>I have an application running on rails 1.9.3 and recently my server was updated and installed a new version of ImageMagick(v 6.8.0-7).</p>
  
  <p>After this my application started throwing an exception when Magick::Image.from_blob() is called:</p>
  
  <p>"Magick::ImageMagickError (NoDecodeDelegateForThisImageFormat `' @ error/blob.c/BlobToImage/361):"</p>
  
  <p>I updated Rmagick to the latest gem version(2.13.2) but it did not solve the problem</p>
  
  <p>does anybody ran into the same problem! On the log of what changed in ImageMagick there is nothing related to this and neither on Rmagick!</p>
  
  <p>If you have any clue please help!</p>
  
  <p>all the best,</p>
  
  <p>Andre</p>