On fzf.vim opening in new cmd Window in Git Bash

[ykhan21]

Checklist

• I have read through the manual page (man fzf)
• I have searched through the existing issues
• For bug reports, I have checked if the bug is reproducible in the latest version of fzf

Output of fzf --version

0.52.1 (6432f00)

OS

• Linux
• macOS
• Windows
• Etc.

Shell

• bash
• zsh
• fish

Problem / Steps to reproduce

This PR made by @Konfekt allows fzf.vim to work in Git Bash.
However, I found that by commenting the following part of the if-branch allows fzf.vim with the stock vim in Git Bash to run normally.

fzf/plugin/fzf.vim

Lines 711 to 716 in daa6024

	elseif has('win32unix') && $TERM !=# 'cygwin'
	let shellscript = s:fzf_tempname()
	call s:writefile([command], shellscript)
	let command = 'cmd.exe //C '.fzf#shellescape('set "TERM=" & start /WAIT sh -c '.shellscript)
	let a:temps.shellscript = shellscript
	endif

In Git Bash's vim, :echo has('unix') returns 1, :echo has('win32unix') returns 1, :echo has('win32') returns 0, and :echo has('win64') returns 0.

What is has('win32unix') used for? It seems like it can be removed in a few cases.

[Konfekt]

This checks for the Win32 version of Vim, using Unix files (Cygwin), according to :help feature-list, but Cygwin nowadays rather refers to MSYS2.
One striking difference is that it expects Unix paths.

As vim in Git Bash is the default Vim, we looked no further.
By has('win32unix') being true, we know not only that this is most likely Git Bash vim, but also that the Git Bash executable exists, used by line 714.

So yes, one could likely check for something like has('win32unix') || (has('win32') && &shell =~# '\v<(ba)?sh>') instead of has('win32unix')

Likely only its original author @janlazo can tell us why $TERM !=# 'cygwin' must be ensured.

[ykhan21]

Why does it need to be run as a cmd.exe process?

Removing this branch lets Git Bash's vim use the unix branches and most importantly does not cause a separate cmd.exe Window to appear.

[Konfekt]

Removing this branch lets Git Bash's vim use the unix branches and most importantly does not cause a separate cmd.exe Window to appear.

Is it? What does branch refer to? If you mean spawning cmd.exe, that would be great.
Again, this code was added in #933 whose authors know better. The Wiki says

On Cygwin, install script will download the prebuilt fzf binary for Windows platform. It does not run on mintty, the default terminal emulator shipped with Cygwin, but it works fine on ConEmu or the default Command Prompt (cmd.exe).

The Vim plugin of fzf also works with the Windows binary. It will start an extra cmd.exe window on mintty to circumvent the aforementioned limitation.

but seems somewhat outdated, since now the dev branch already supports Fzf in Git Bash default Mintty term.

Mind that #3804 asks similarly if the spawning of cmd.exe could be removed.
Maybe with the latest changes this is indeed possible.
For starters, does

let command = 'start /WAIT sh -c '.shellscript 

suffice?

[Konfekt]

If I understand correctly, in latest Git Bash simply

execute 'silent !'.command

instead of the involved cmd.exe shell script execution suffices.
Did you check :FZF to work as expected for all kind of paths, namely with spaces?

[ykhan21]

Yes, see the image below:

However, it executes it in full screen. Is this is normal behavior on a unix system or is this an artifact of some other has('win32unix') check?

[Konfekt]

For me :FZF $path without the above shown if-branch worked out-of-the-box in Windows Terminal, but not in Git Bash's default Mintty terminal.
However, it did with the exe from the dev branch using winpty.
Therefore I suspect that this if-branch was needed to make fzf work in Git Bash without winpty (which maybe wasn't included in Git bash from the start?) and we can drop it together with the next release.

If you could confirm that all commands work as expected under the Git Bash Terminal as well?

[Konfekt]

@junegunn

Therefore I suspect that this if-branch was needed to make fzf work without winpty in Git Bash (which maybe wasn't included in Git bash from the start?) and we can drop it together with the next release.

Maybe that could be part of the next release since it yet improves again on the Git Bash experience

[Konfekt]

Since 573df52 (#3807) seems to call winpty directly, the check for win32unix could be replaced by executable('winpty').

This would also make it clearer, if guessed correctly, why all the convolution

fzf/plugin/fzf.vim

Lines 711 to 716 in daa6024

	elseif has('win32unix') && $TERM !=# 'cygwin'
	let shellscript = s:fzf_tempname()
	call s:writefile([command], shellscript)
	let command = 'cmd.exe //C '.fzf#shellescape('set "TERM=" & start /WAIT sh -c '.shellscript)
	let a:temps.shellscript = shellscript
	endif

had to be added in the first place, when likely neither winpty was an option nor Windows Terminal was widely used.

[junegunn]

@Konfekt Can you open a pull request against devel branch?

[ykhan21]

Interestingly, I can use fzf in Git Bash without winpty. I don't know why that is.

0.52.1 (6432f00)

fzf also works for me with no ~/.bashrc.

[Konfekt]

Phew, to confirm: that might be because this terminal is from MSYS2 itself, not the somewhat more restricted Git Bash MSYS2? For most users, Vim in MSYS2 will be Vim in Git Bash, so that's a case to be accounted for.

[ykhan21]

This is the Git Bash terminal from Git for Windows. It is from scoop install git.

[Konfekt]

I can confirm that fzf.exe 0.52.1 works in Git Bash Mintty under Windows 11; it does not under Window 10.