fn_transform filtering is broken

[ibhagwan]

One thing I noticed when experimenting with multiprocess=false, if fn_transform returns nil, sometimes other items returned by fn_transform won't render. I'm able to reproduce with this:

-- renders nothing
fzf_lua.fzf_exec("echo 'one\ntwo\nthree\nfour\n'", {
  fn_transform = function(item)
    if item == "three" then
      return
    end
    return item
  end,
})

-- renders one, two, three as expected
fzf_lua.fzf_exec("echo 'one\ntwo\nthree\nfour\n'", {
  fn_transform = function(item)
    if item == "four" then
      return
    end
    return item
  end,
})

Is that intentional, is there a new way to filter out items?

Originally posted by @elanmed in #2174 (reply in thread)