Renamed file considered deleted inside directory junction #3279

How are you using the lua-language-server?

NeoVim

Which OS are you using?

Windows

What is the issue affecting?

Other

Expected Behaviour

LS correctly works with files inside directory junction or symlinks.

Actual Behaviour

LS functionality stops working after saving such a file in editor.

Reproduction steps

1. Enable LuaLS in NeoVim.
2. Put NeoVim config files inside directory junction. E.g. I have init.lua file in directory C:\dev\dotfiles\nvim and I've created the junction to that directory in C:\Users\RobotComp.ru\AppData\Local\nvim. NVim reads config files from C:\Users\RobotComp.ru\AppData\Local\nvim.
3. Open init.lua in NVim, change something and save it with :w command.
4. After that, any interactions with LS stop working (hover, go to definition, etc.)
5. If I re-edit file with :e % command, everything starts working again.

Additional Notes

I did some research and found the following.

When saving init.lua, NVim renames it several times (to init.lua~ and back). Don't know why.
The logs (see error.log) show that the filewatch(rename) function is called on LS, which calls isExists().
And although the file exists, isExists() returns false, so the file is considered deleted, and the LS "forgets" about it.

More specifically, the problem occurs in script/filewatch.lua:18:

if res :string():gsub('^%w+:', string.lower)
~= path:string():gsub('^%w+:', string.lower) then
return false
end

Here, it turns out that res contains the actual path to the file (C:\dev\dotfiles\nvim\init.lua), and path contains the path with the junction (C:\Users\RobotComp.ru\AppData\Local\nvim\init.lua).

Commenting out these lines makes everything work correctly (see fixed.log). However, I didn't make a PR with such changes because I didn't fully understand why this path comparison was needed at all. It seems like it fixes some other bug?

Thanks in advance :)

Log File

[00:20:20.415][debug][#0:script\filewatch.lua:98]: filewatch: rename C:\Users\RobotComp.ru\AppData\Local\nvim\init.lua
[00:20:20.415][debug][#0:script\filewatch.lua:98]: filewatch: modify C:\Users\RobotComp.ru\AppData\Local\nvim\init.lua
[00:20:20.415][debug][#0:script\filewatch.lua:98]: filewatch: rename C:\Users\RobotComp.ru\AppData\Local\nvim\init.lua~
[00:20:20.415][debug][#0:script\workspace\workspace.lua:592]: FileChangeType.Deleted file:///c%3A/Users/RobotComp.ru/AppData/Local/nvim/init.lua
[00:20:20.416][debug][#0:script\workspace\workspace.lua:592]: FileChangeType.Deleted file:///c%3A/Users/RobotComp.ru/AppData/Local/nvim/init.lua~

error.log
fixed.log