Fails to parse diffs with submodule changes

[jedrzejboczar]

Description

I get an error when commit diff includes submodule changes (when opening a commit from log view), e.g.

....local/share/nvim/lazy/neogit/lua/neogit/lib/git/log.lua:53: Failed to parse line: Submodule frontend d1c3dff..1b6f4c8: 

This does not happen if submodule changes are shown at the end of the diff, then they are just ignored, while they should be displayed.

Neovim version

NVIM v0.11.0-dev-381+gfb6c059dc5
Build type: Release
LuaJIT 2.1.1716656478

Operating system and version

Arch Linux \r (\l)

Steps to reproduce

1. Find or create a repository with submodules, e.g. I found https://github.com/viniceosm/trainning-submodules which can be used to reproduce.
2. Open neogit log view, then open a commit that updates submodules and has submodule changes before any diffs, e.g. viniceosm/trainning-submodules@d962cd9.
3. You will get an error.

Expected behavior

Should parse the diff and also should display foldable submodule changes.

Actual behavior

Parsing fails if Submodule... line is before any diff... lines, otherwise submodule changes will be ignored.

Minimal config

-- NOTE: See the end of this file if you are reporting an issue, etc. Ignore all the "scary" functions up top, those are
-- used for setup and other operations.
local M = {}

local base_root_path = vim.fn.fnamemodify(debug.getinfo(1, "S").source:sub(2), ":p:h") .. "/.min"
function M.root(path)
  return base_root_path .. "/" .. (path or "")
end

function M.load_plugin(plugin_name, plugin_url)
  local package_root = M.root("plugins/")
  local install_destination = package_root .. plugin_name
  vim.opt.runtimepath:append(install_destination)

  if not vim.loop.fs_stat(package_root) then
    vim.fn.mkdir(package_root, "p")
  end

  if not vim.loop.fs_stat(install_destination) then
    print(string.format("> Downloading plugin '%s' to '%s'", plugin_name, install_destination))
    vim.fn.system({
      "git",
      "clone",
      "--depth=1",
      plugin_url,
      install_destination,
    })
    if vim.v.shell_error > 0 then
      error(string.format("> Failed to clone plugin: '%s' in '%s'!", plugin_name, install_destination),
        vim.log.levels.ERROR)
    end
  end
end

---@alias PluginName string The plugin name, will be used as part of the git clone destination
---@alias PluginUrl string The git url at which a plugin is located, can be a path. See https://git-scm.com/book/en/v2/Git-on-the-Server-The-Protocols for details
---@alias MinPlugins table<PluginName, PluginUrl>

---Do the initial setup. Downloads plugins, ensures the minimal init does not pollute the filesystem by keeping
---everything self contained to the CWD of the minimal init file. Run prior to running tests, reproducing issues, etc.
---@param plugins? table<PluginName, PluginUrl>
function M.setup(plugins)
  vim.opt.packpath = {}                      -- Empty the package path so we use only the plugins specified
  vim.opt.runtimepath:append(M.root(".min")) -- Ensure the runtime detects the root min dir

  -- Install required plugins
  if plugins ~= nil then
    for plugin_name, plugin_url in pairs(plugins) do
      M.load_plugin(plugin_name, plugin_url)
    end
  end

  vim.env.XDG_CONFIG_HOME = M.root("xdg/config")
  vim.env.XDG_DATA_HOME = M.root("xdg/data")
  vim.env.XDG_STATE_HOME = M.root("xdg/state")
  vim.env.XDG_CACHE_HOME = M.root("xdg/cache")

  -- NOTE: Cleanup the xdg cache on exit so new runs of the minimal init doesn't share any previous state, e.g. shada
  vim.api.nvim_create_autocmd("VimLeave", {
    callback = function()
      vim.fn.system({
        "rm",
        "-r",
        "-f",
        M.root("xdg")
      })
    end
  })
end

-- NOTE: If you have additional plugins you need to install to reproduce your issue, include them in the plugins
-- table within the setup call below.
M.setup({
  plenary = "https://github.com/nvim-lua/plenary.nvim.git",
  telescope = "https://github.com/nvim-telescope/telescope.nvim",
  diffview = "https://github.com/sindrets/diffview.nvim",
  neogit = "https://github.com/NeogitOrg/neogit"
})
-- WARN: Do all plugin setup, test runs, reproductions, etc. AFTER calling setup with a list of plugins!
-- Basically, do all that stuff AFTER this line.
require("neogit").setup({}) -- For instance, setup Neogit

[jedrzejboczar]

Looks like the submodule "diff" can include commit messages, e.g.

Submodule frontend d1c3dff..1b6f4c8:
  > fix: improve display on small screens

or not (as in the example repo that I linked in reproduction steps, git show --format=fuller d962cd9):

Submodule lib/logpty cc45b46...292c2ed (commits not present)