Line in commit message that starts with a number confuses the auto indentation

[ericonr]

Originally in https://github.com/neovim/neovim/issues/18396

Steps to reproduce:

• Set neovim as your git editor
• Run git commit
• Copy the commit message from https://github.com/lnls-dig/openMMC/pull/126/commits/fc56dedffff4781e4b0c06594f358aedb7cfe957
• Select the commit body and press gq to auto format it

The commit message in question:

fpga_spi: guarantee board_diagnostic_t alignment

fpga_spi.c reads from this struct by aliasing it to an uint32_t pointer
and using that to iterate through it. That means it should be aligned to
4 bytes, to so the reads don't generate faults, and that its size should
be a multiple of 4, otherwise we'd have to deal with defining incomplete
reads for the last element.

The commit body is changed to:

fpga_spi.c reads from this struct by aliasing it to an uint32_t pointer
and using that to iterate through it. That means it should be aligned to
4 bytes, to so the reads don't generate faults, and that its size should
  be a multiple of 4, otherwise we'd have to deal with defining
  incomplete reads for the last element.

Per https://github.com/neovim/neovim/issues/18396#issuecomment-1116741530 , this might not be possible to fix (or even considered a bug):

This is because the ftplugin for gitcommit sets formatoptions+=n and formatlistpat

But I'd like to bring it up to confirm.

[tpope]

Vim's default 'formatlistpat' does this. You can change it in your vimrc to achieve the desired effect:

set formatlistpat=^\\s*\\d\\+[\\]:.)}]\\s\\+

I'm on the fence about whether ftplugin/gitcommit.vim should itself change this. The problem isn't "the default 'formatlistpat' is bad for gitcommit files" but rather "the default 'formatlistpat' is bad for almost all files." I suppose we can try it on master for a bit and see if anyone complains.

[ericonr]

Thanks you!