Bash completion for git diff git suggests only top-level completions

[martinvonz]

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• I have searched the open and rejected issues

Rust Version

1.63.0

Clap Version

3.2.22

Minimal reproducible code

use std::io::{stdout, Write};
use clap;
use clap::CommandFactory;

#[derive(clap::Parser, Clone, Debug)]
enum App {
    Diff,
}

fn main() {
    let mut app = App::command();
    let mut buf = vec![];
    clap_complete::generate(clap_complete::Shell::Bash, &mut app, "git", &mut buf);
    stdout().write_all(&mut buf).unwrap();
}

Steps to reproduce the bug with the above code

Run the command and source the generated script. Then enter git diff git <TAB>

Actual Behaviour

The suggestions include diff.

Expected Behaviour

The suggestions should not include diff.

Additional Context

This is a bug in the Bash completion script I noticed while working on #4265. The issue is that the initial processing loop in the generated Bash script resets the "command so far" variable ($cmd) to git whenever git appears in the list, so it provides suggestions for the top-level command.

Debug Output

No response