owncloud/core — pull request #11200 by georgehrke (2014-09-21 15:32:40+00:00)
Title: make sure preview prop is instanceof OC_Image before using it in showPreview

fixes https://github.com/owncloud/core/issues/10012

wasn't able to reproduce it, but this patch makes sure the error doesn't occur

please review @icewind1991 @MorrisJobke @oparoz