nvim_open_win cursor-relative position depends on buffer text

[anuvyklack]

Describe the bug

Today I updated to Neovim v0.8.2 and my fold-preveiw plugin stopped working as it should. I haven't updated the plugin since November.

The plugin should open float window with folded region preview indented the same way the folded code is. But now all float windows are opened in the zero column. I am not the only one who faced this issue.

The plugin is quite simple and contains only one file. The code point that open a window.

I made some research and found that the nvim_open_win api function is broken.

I open Neovim with nvim --clean and execute next command in different places of the buffer

:lua vim.api.nvim_open_win(0, false, { 
    anchor = 'NW',
    border = 'rounded',
    relative = 'win',
    bufpos = vim.api.nvim_win_get_cursor(0),
    width = 25,
    height = 10
})

The command should open the float window under the cursor. If there is a text in the place when float window should appear, then its position would be correct:

But if there is no text, then float window sticks to the last letter.
Look at the cursor position and at the float window position.

Steps to reproduce

nvim --clean file.txt

Execute next command at the end of the most long line, so that all below lines are shorter,

:lua vim.api.nvim_open_win(0, false, { anchor = 'NW', border = 'rounded', relative = 'win', bufpos = vim.api.nvim_win_get_cursor(0), width = 25, height = 10 })

Expected behavior

The floating window should open such that it left upper corner should appear one line under the cursor position.

Neovim version (nvim -v)

0.8.2

Vim (not Nvim) behaves the same?

Operating system/version

fedora 36

Terminal name/version

kitty 0.26.5

$TERM environment variable

tmux-256color

Installation

dnf

[justinmk]

Today I updated to Neovim v0.8.2

is this a regression compared to 0.8.1, i.e. did it work for you in 0.8.1 (else please say which version worked for you)?

If there is a text in the place when float window should appear, then its position would be correct:

so it looks like the issue depends on presence of text in the buffer.

"nvim_open_win is broken!" is a bit much, in the future please choose a more precise issue title.

[zeertzjq]

You need to subtract by one when passing line number returned by nvim_win_get_cursor. That it worked as expected for you previously is a bug.

[anuvyklack]

No. The problem is not the line position. And I subtracted one, so this behavior was correct.

The problem is column position.

[anuvyklack]

@zeertzjq, you get it wrong, the issue is still here!

[clason]

Well, I'd argue that you were first to get the minimal reproducing example wrong. First step would be to correct that.

To be clear, the behavior you showed here (code + screenshots) is the expected behavior and not an error.

[zeertzjq]

If the anchored buffer text position is in a fold than the previous behavior makes even less sense.

[anuvyklack]

Ok, maybe you're right, and there was a bug that I relied on.

[anuvyklack]

Anchored buffer text position was not inside fold, but first line of the fold, which is available, as I understand.