Fix issue where error is shown in fzf v0.56.1 or later

[hexium310]

After fzf v0.56.1, in all situations, shown completions are paths, and the following error is displayed.

__fzf_extract_command:3: compstate: assignment to invalid subscript range

_fzf_extract_command has been rewritten and is no longer directly called, which is the cause of this issue. This PR replaces it with the global $cmd_word according to the change of fzf.

ref: junegunn/fzf@57c08d9

[hexium310]

Not the result of fzf --version but $(which __fzf_extract_command) is used because there may be who are fetching only completion.zsh` such as me. https://github.com/hexium310/dotfiles/blob/6b61cdf90e49bb08824dcd779370436189cf010e/config/zsh/.zshrc#L23

[chitoku-k]

Thanks for your effort on your investigation and modification so as to keep up with the latest version of fzf. How about checking the existence of the cmd_word variable rather than the body of the completion function? This should make much more sense as it finally adopts the value of the variable anyway when it found one.

[chitoku-k]

Can we use parameter expansion there for simplicity?

[chitoku-k]

As I briefly tested this PR, I don’t think this is enough to support the commit you mentioned (junegunn/fzf@57c08d9).

Let’s think of this example:

$ git checkout master; git fetch **<TAB>

[hexium310]

The completion of the second and subsequent executions may not be supported on the master branch either.

git checkout master
# v0.56.0 doesn't have the change of __fzf_extract_command
source <(curl -L https://github.com/junegunn/fzf/raw/refs/tags/v0.56.0/shell/completion.zsh) fzf-zsh-completions.plugin.zsh

[chitoku-k]

OK, let’s merge this now and add support for the new completion available since fzf v0.56.1 later on.