xolox/vim-session — pull request #83 by inkarkat (2013-12-16 16:35:22+00:00)
Title: Don't leave behind empty tab page when :AppendTabSession is unsuccessful.

Make `xolox#session#open_cmd()` indicate the success (and whether a warning message was given) via its return value. Check that in `xolox#session#append_tab_cmd()` and undo the opening of the new tab page in case no session was opened.