commit https://github.com/vim/vim/commit/d424747d5821c2873e24d25d3407d08b25ea3443 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Nov 2 13:28:59 2015 +0100 patch 7.4.905 Problem: Python interface can produce error "vim.message' object has no attribute 'isatty'". Solution: Add dummy isatty(), readable(), etc. (closes #464)

Tests for writefile()

STARTTEST
:source small.vim
:%delete _
:let f = tempname()
:call writefile(["over","written"], f, "b")
:call writefile(["hello","world"], f, "b")
:call writefile(["!", "good"], f, "a")
:call writefile(["morning"], f, "ab")
:call writefile(["", "vimmers"], f, "ab")
:bwipeout!
:$put =readfile(f)
:1 delete _
:w! test.out
:qa!
ENDTEST