Completion popup behavior is wonky

[raghur]

First of all, great project... very promising. I've been trying to use this along with neovim-qt.
This issue with completion popup behavior... I initially thought that this might be a Coc.nvim or vim-go issue - but with neovim-qt since things work properly, this seems to be a UI issue.

1. In a go file with Coc.nvim installed, typing the first letter completes the entire word - so you then have to backspace over
   https://i.imgur.com/VlYZT8S.mp4

2. With a json file, the above behavior isn't seen - but selecting a completion results in malformed json (quotes are incorrectly placed at the end of the json value as well)

3. Overall, behavior of the popup in json file flickers a lot.

My nvim version:

NVIM v0.5.0-229-ged424655b
Build type: RelWithDebInfo
LuaJIT 2.1.0-beta3
Compilation: C:/Program Files (x86)/Microsoft Visual Studio/2017/Community/VC/Tools/MSVC/14.16.27023/bin/Hostx86/x64/cl.exe /DWIN32 /D_WINDOWS /W3 /MD /Zi /O2 /Ob1 /DNDEBUG /W3 -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE -DWIN32 -D_WIN32_WINNT=0x0600 -DINCLUDE_GENERATED_DECLARATIONS -DUTF8PROC_STATIC -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -DMIN_LOG_LEVEL=3 -IC:/projects/neovim/build/config -IC:/projects/neovim/src -IC:/projects/nvim-deps/usr/include -IC:/projects/neovim/build/src/nvim/auto -IC:/projects/neovim/build/include

So i tried to record a screencast of the JSON behavior and discovered that this seems to be triggered only after I visit a go file and try completions there

https://imgur.com/a/1ZHDty1

OTOH, the behavior still isn't there when I try it with neovim qt so seems like a bad interaction/some internal state corruption in fvim?

[yatli]

thanks for reporting the problem. looks like the first entry is triggered too eagerly.
investigating.

[yatli]

can you confirm that with neovim-qt it uses the external popup menu?

[yatli]

you can also try disabling the ext-popup menu in FVim to see if the problem disappears.

[yatli]

I also observe some weird behavior.
If is held and the selection changes fast, it kind of bounces back and forth and then stays on an old index (instead of going further down the list).