commit https://github.com/vim/vim/commit/5983ad0b038fa689653246cb304fd43e8ae39a78 Author: Bram Moolenaar <Bram@vim.org> Date: Sat Mar 5 20:54:36 2016 +0100 patch 7.4.1493 Problem: Wrong callback invoked for zero-id messages. Solution: Don't use the first one-time callback when the sequence number doesn't match.

Test A:
  - file name displayed: test://bar.txt
  - quickfix claims that the file name displayed is: test://bar.txt
Test B:
  - number of window open: 2
Test C:
  - 'buftype' of the location list window: quickfix
  - buffer displayed in the 2nd window: test://quux.txt