Re: [PATCH] diff: ensure correct lifetime of external_diff_cmd

Eric Sunshine [off-list ref] writes:

However, you might also consider using xstrdup_or_null(), like this:

    external_diff_cmd = xstrdup_or_null(getenv(...));
    if (!external_diff_cmd)
        ...as before...

quoted

        done_preparing = 1;
        return external_diff_cmd;
 }

Looks good.