bug: grid border errors when pipe_table.wrap = false

Read lua/render-markdown/render/markdown/table.lua around border_row and the parser logic that populates data.prefixes when wrapping is enabled. Compare the existing grid table test with the proposed wrap = false case, then run the table tests. Done means grid tables render with body separators and no error when wrapping is disabled, including inside list items.

Neovim version (nvim -v)

0.12.6

Neovim distribution

N/A (custom config, vim.pack)

Operating system

macOS 27.2

Terminal emulator / GUI

Any. Reproduced in an automated PTY harness and in the plugin's own test runner.

Describe the bug

With pipe_table.grid = true and pipe_table.wrap = false, rendering a table fails on every pass and the table is never rendered. wrap = false is a documented option (the default grid = true + wrap = true combination works), so the two seem expected to compose.

The error comes from the body separator added by grid: Render:border_row appends the row prefix unconditionally for position == 'body':

attempt to index local 'other' (a nil value)
  lua/render-markdown/lib/line.lua:39 in function 'extend'
  lua/render-markdown/render/markdown/table.lua:247 in function 'border_row'
  lua/render-markdown/render/markdown/table.lua:47 in function 'run'

Parser:parse only fills data.prefixes inside if layout.wrap then, so with wrap = false the table is empty and prefixes[row.node.start_row] is nil.

Reproduction, with pipe_table = { grid = true, wrap = false }:

| A | B |
| --- | --- |
| 1 | 2 |
| 3 | 4 |

The same happens inside a list item, and border_virtual = true does not matter.

Adding a test case that mirrors the existing grid test but with wrap = false reproduces it in the repo test suite:

it('grid without wrap', function()
    util.setup.text(lines, { pipe_table = { grid = true, wrap = false } })
    ...

Expected behavior

Table renders with a separator line between body rows, aligned to the table start column, without errors.

Healthcheck output

render-markdown.nvim [versions] ~
- ✅ OK neovim >= 0.11
- ✅ OK tree-sitter ABI: 15
- ✅ OK plugin: 8.14.12

render-markdown.nvim [configuration] ~
- ✅ OK valid

render-markdown.nvim [tree-sitter markdown] ~
- ✅ OK parser: installed
- ✅ OK ABI: 15
- ✅ OK highlights: ~/.local/share/nvim/site/queries/markdown/highlights.scm
- ✅ OK highlighter: enabled

render-markdown.nvim [tree-sitter markdown_inline] ~
- ✅ OK parser: installed
- ✅ OK ABI: 15
- ✅ OK highlights: ~/.local/share/nvim/site/queries/markdown_inline/highlights.scm

render-markdown.nvim [icons] ~
- ✅ OK using: mini.icons

render-markdown.nvim [conflicts] ~
- ✅ OK headlines: not installed
- ✅ OK markview: not installed
- ✅ OK obsidian: not installed

Plugin configuration

require('render-markdown').setup({
    pipe_table = { border_virtual = true, wrap = false, grid = true },
})

Also fails with the minimal config below (no border_virtual):

require('render-markdown').setup({
    pipe_table = { wrap = false, grid = true },
})

Plugin error log

Error in command line:
vim.schedule callback: ./lua/render-markdown/lib/line.lua:39: attempt to index local 'other' (a nil value)
stack traceback:
	./lua/render-markdown/lib/line.lua:39: in function 'extend'
	./lua/render-markdown/render/markdown/table.lua:247: in function 'border_row'
	./lua/render-markdown/render/markdown/table.lua:47: in function 'run'
	./lua/render-markdown/render/base.lua:21: in function 'execute'
	./lua/render-markdown/handler/markdown.lua:58: in function 'callback'
	./lua/render-markdown/request/view.lua:76: in function 'callback'
	./lua/render-markdown/request/view.lua:88: in function 'query'
	./lua/render-markdown/request/view.lua:71: in function 'nodes'
	./lua/render-markdown/handler/markdown.lua:55: in function 'parse'
	./lua/render-markdown/core/handlers.lua:94: in function 'tree'
	./lua/render-markdown/core/handlers.lua:51: in function 'run'
	./lua/render-markdown/core/ui.lua:156: in function 'callback'
	./lua/render-markdown/request/view.lua:64: in function 'parse'
	./lua/render-markdown/core/ui.lua:153: in function 'parse'
	./lua/render-markdown/core/ui.lua:126: in function 'render'
	./lua/render-markdown/core/ui.lua:112: in function 'run'
	./lua/render-markdown/core/ui.lua:78: in function <./lua/render-markdown/core/ui.lua:77>