commit https://github.com/vim/vim/commit/12c4492dd35e0cd83c8816be2ec849b836109882 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jan 8 13:26:03 2017 +0100 patch 8.0.0151: passing buffer content to system() is clumsy Problem: To pass buffer content to system() and systemlist() one has to first create a string or list. Solution: Allow passing a buffer number. (LemonBoy, closes #1240)

Results of test83
case1: ok
case2: ok
case3: ok