Image is stretched when zooming on an already zoomed in image

[mdamien]

Instructions by the user who reported the issue:

Step 1 – Just open any small picture with your extension: http://jpegshare.net/8a/c4/8ac4bbe73ea804f6df718e07228b1f39.jpg.html

Step 2 – Zoom the picture to 500%: http://jpegshare.net/64/55/6455d9e0f8eaa6b5a9b83355bd39c99f.jpg.html

Step 3 – Click on the picture with the left mouse button. The result: http://jpegshare.net/38/a2/38a2badfa3f862b7412d5fbd41788550.jpg.html

Should be like this: http://jpegshare.net/7b/80/7b80fcb76dbed934f19757c8b35f2804.jpg.html

Example: http://jpegshare.net/images/c2/bc/c2bc431b8f3a16cdcfbc5f2938834c88.jpg