Created attachment 8574353 [details] testcase.html User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.76 Safari/537.36 Steps to reproduce: 1. Create a contenteditable element divided over columns with -moz-column. 2. Press down at the end of a column, or up at the beginning of a column. See reduced testcase. Actual results: The cursor jumps to the end/beginning of the contenteditable. (In some cases, this selection appears to be "invalid"; it can't normally be created with the mouse, and/or the contenteditable loses focus.) Expected results: The cursor should jump to the next/previous column. Left/right keys work fine.