patch 8.0.0732: when updating a buffer modeless selection is lost commit https://github.com/vim/vim/commit/80dd3f9d41ce2ff6ab3544cdb266627bbdfc34a6 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Jul 19 12:51:52 2017 +0200 patch 8.0.0732: when updating a buffer modeless selection is lost Problem: When updating a buffer for a callback the modeless selection is lost. Solution: Do not insert or delete screen lines when redrawing for a callback and there is a modeless selection.

" Tests for complicated + argument to :edit command
function Test_edit()
  call writefile(["foo|bar"], "Xfile1") 
  call writefile(["foo/bar"], "Xfile2") 
  edit +1|s/|/PIPE/|w Xfile1| e Xfile2|1 | s/\//SLASH/|w
  call assert_equal(["fooPIPEbar"], readfile("Xfile1"))
  call assert_equal(["fooSLASHbar"], readfile("Xfile2"))
endfunction