(coc.nvim + clangd) Semantic highlighting seems to cut off when entering insert mode in NeoVim

[RMichelsen]

Describe the bug
Im experiencing some weird behaviour with the highlighting, whenever I enter
insert mode, the semantic highlighting disappears for all text above the cursor.

To Reproduce
Open any .cpp file with coc.nvim/clangd + vim-lsp-cxx-highlight.
Observe that semantic highlighting works properly, then enter
insert mode.

Screenshots

Configuration (Fill this out):

• Neovim NVIM v0.5.0-372-ge63b25eb2
• coc.nvim + clangd (10.0.0) Windows 10 binaries

Log File:

4/13/2020 4:14:06 AM: lsp_cxx_hl beginning initialization...
4/13/2020 4:14:06 AM: vim-lsp not detected
4/13/2020 4:14:06 AM: LanguageClient-neovim not detected
4/13/2020 4:14:06 AM: coc.nvim successfully registered
4/13/2020 4:14:06 AM: nvim-lsp successfully registered
4/13/2020 4:14:07 AM: textprop nvim notify symbols for .\AppEditorLogic.cpp
4/13/2020 4:14:07 AM: hl_symbols (textprop nvim) highlighted 18 symbols in file .\AppEditorLogic.cpp
4/13/2020 4:14:07 AM: operation hl_symbols (textprop nvim) .\AppEditorLogic.cpp took   0.002619s to complete
4/13/2020 4:14:10 AM: textprop nvim notify symbols for .\AppEditorLogic.cpp
4/13/2020 4:14:10 AM: hl_symbols (textprop nvim) highlighted 12 symbols in file .\AppEditorLogic.cpp
4/13/2020 4:14:10 AM: operation hl_symbols (textprop nvim) .\AppEditorLogic.cpp took   0.001566s to complete

[jackguo380]

Hi R-Michelsen,

Thanks for reporting this. I just tested out NVIM v0.5.0-429-g13b4a6fd4 with clangd 11 and am seeing a similar issue. The highlighting will disappear from the buffer after entering insert mode and typing anything.

I suspect the cause is related to my comment on coc-clangd about incremental highlighting. @fannheyward Maybe having coc-clangd cache previous highlighting messages then calling lsp_cxx_hl#hl#notify_symbols would fix this issue. What do you think?

For now if you want something that works clangd 9.0.0 shouldn't have this problem as long as you are willing to downgrade to it.

[sam-mccall]

Maybe having coc-clangd cache previous highlighting messages then calling lsp_cxx_hl#hl#notify_symbols would fix this issue. What do you think?

Indeed, fixed in clangd/coc-clangd@008da37 and it seems to work well.
We need a new release of coc-clangd though, hopefully soon.

[fannheyward]

coc-clangd has released a new version with this fix.

[jackguo380]

Just tested it out as well, looks like it is fixed.

Thanks @sam-mccall @fannheyward

@R-Michelsen if updating to the latest coc-clangd fixes it for you please close the issue.