Bug: Git diff doesn't work if file name contains spaces

[kris-swann]

Self Checks

• I'm using the latest lualine.
• [ x] I didn't find the issue in existing issues or PRs.

How to reproduce the problem

• Create a new git directory
  • git init test && cd test
• Create two new files one with spaces, one without
  • echo "test\ntest\ntest" | tee "test.txt" "test this.txt"
• Commit the two files
  • git add -A && git commit -m "Test this"
• Add two lines to both files
  • echo "test\ntest" | tee -a "test.txt" "test this.txt"
• Copy in the isolated conf, create and view
  • ./nvim_isolated_conf.sh -c foo'
  • ./nvim_isolated_conf.sh -l foo .
  • :PlugInstall
  • :qa
  • ./nvim_isolated_conf.sh -l foo .

Expected behaviour

+2 diff shows in both test.txt and test this.txt

Actual behaviour

+2 diff shows in test.txt but not test this.txt

Minimal config to reproduce the issue

Default config, no changes made

Additional information

I assume it's just a matter of quoting the args here?

lualine.nvim/lua/lualine/components/diff/git_diff.lua

Line 96 in 0a5a668

[[git -C %s --no-pager diff --no-color --no-ext-diff -U0 -- %s]],