No completions after change in insert mode

[blueyed]

Given t.txt:

foo
foobar

And a minimal vimrc:

set runtimepath+=~/.vim/plugged/deoplete.nvim
let g:deoplete#enable_at_startup = 1
call deoplete#enable_logging('DEBUG', '/tmp/deoplete.log')

call deoplete#custom#source('buffer', 'is_debug_enabled', 1)
let g:deoplete#num_processes = 1

call deoplete#custom#option('sources', {
\ '_': ['buffer'],
\})

Starting neovim with nvim -u vimrc.minimal t.txt:

1. press A to append to the first line
2. it shows "foo" and "foobar" as completions
   (3. You can repeat <Esc> and a now, it will keep repeating)
3. insert n
4. the pum will be closed, and the first line is foon now

deoplete is now stuck:

1. backspace will keep "foo", and not offer completions
2. leaving insert mode (<esc>) and using a again will also show no completions

You have to edit the "foo" itself to make it work again.

It looks like a problem in Deoplete._merge_results, but it is not clear to me.

[blueyed]

Tried to bisect, but had to skip a lot due to other issues (i.e. completion was not working at all):

There are only 'skip'ped commits left to test.
The first bad commit could be any of:
700b7f8
ce51f0c
dedcb83
389b625
38b9a65
ab9d231
b299e7d
4fbe097
572fa2c
f3663f1

Seems to be related to the multi-processing in general.

[blueyed]

The first issue (backspace will keep "foo", and not offer completions) can be fixed in Vim/Neovim itself: vim/vim#3193

[Shougo]

Fixed.

[Shougo]

The first issue (backspace will keep "foo", and not offer completions) can be fixed in Vim/Neovim itself: vim/vim#3193

I don't understand the problem...

[blueyed]

Fixed.

Thanks. ´test_800` confirms this (https://github.com/Shougo/deoplete.nvim/pull/807/files#diff-e054dcb6b027ec2cc2fd7a4c6ecf5f5fR102), but needs a sleep for some reason - see the other test above.

vim/vim#3193 is about handling completions via complete() more similar to other completions, i.e. using backspace does not close them.
I am not yet sure if this is good or bad for deoplete though - it might need some form of notification? I do not remember if there are events then (since CompleteDone is not emitted for the closed pum).

[Shougo]

but needs a sleep for some reason - see the other test above.

I think the completion is async and parallel.

vim/vim#3193 is about handling completions via complete() more similar to other completions, i.e. using backspace does not close them.

For deoplete, the feature is not useful.
Because deoplete must re-generate candidates when you press <BS>.
So you need to remap <BS> key like this.

inoremap <expr><BS> deoplete#smart_close_popup()."\<C-h>"