Bug: sources.providers.buffer.opts.get_bufnrs cannot deal with multiple buffers

[chrisgrieser]

Make sure you have done the following

• I have updated to the latest version of blink.cmp
• I have read the README

Bug Description

When setting sources.providers.buffer.opts.get_bufnrs to something that returns multiple buffer numbers, you regularly get this error:

failed to get completions with error: ...are/nvim/lazy/blink.cmp/lua/blink/cmp/sources/buffer.lua:18: attempt to index local 'line' (a nil value)

The issue seems to be caused by this:

blink.cmp/lua/blink/cmp/sources/buffer.lua

Lines 10 to 18 in 6e9fb62

	local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
	-- exclude word under the cursor
	local line_number = vim.api.nvim_win_get_cursor(0)[1]
	local column = vim.api.nvim_win_get_cursor(0)[2]
	local line = lines[line_number]
	local start_col = column
	while start_col > 1 do
	local char = line:sub(start_col, start_col)

I think the issue arises from line_number being the current line number of the current window where the cursor is (line 13), but then being used to index lines, which are the lines of any buffer passed (line 10). Thus, the error occurs when the cursor is currently on line n, while there is a different buffer passed by get_bufnrs that has fewer than n lines. In this case line[line_number] is nil and consequently errors on line 18, explaining the error message.

Relevant configuration

sources = {
	providers = {
		buffer = {
			opts = {
				get_bufnrs = function()
					local allOpenBuffers = vim.fn.getbufinfo { buflisted = 1, bufloaded = 1 }
					local allBufs = vim.iter(allOpenBuffers)
						:filter(function(buf) return vim.bo[buf.bufnr].buftype == "" end)
						:map(function(buf) return buf.bufnr end)
						:totable()
					return allBufs
				end,
			},
		},
	},
},

neovim version

NVIM v0.10.2

blink.cmp version: branch, tag, or commit

0.7.1