Re: [PATCH 2/2] help: make option --help open man pages only for Git commands

[Ralf Thielow <ralf.thielow@gmail.com>]

Sorry for being late in responding. It's been busy days.

2016-08-18 21:51 GMT+02:00 Junio C Hamano <gitster@pobox.com>:
> Ralf Thielow <ralf.thielow@gmail.com> writes:
>
> The same comment applies to 1/2, too, in that the word "command"
> will be interpreted differently by different people.  For example,
> "git co --help" and "git help co" would work, with or without 1/2 in
> place when you have "[alias] co = checkout", so we are calling "Git
> subcommands that we ship, custom commands 'git-$foo' the users have
> in their $PATH, and aliases the users create" collectively "command".
>
> As long as the reader understands that definition, both the log
> messages of 1/2 and 2/2 _and_ the updated description for "git help"
> we have in 1/2 are all very clear.  I do not care too much about the
> commit log message, but we may want to think about the documentation
> a bit more.
>
> Here is what 1/2 adds to "git help" documentation:
>
>     +Note that `git --help ...` is almost identical to `git help ...` because
>     +the former is internally converted into the latter with option --command-only
>     +being added.
>
>      To display the linkgit:git[1] man page, use `git help git`.
>
>     @@ -43,6 +44,10 @@ OPTIONS
>             Prints all the available commands on the standard output. This
>             option overrides any given command or guide name.
>
>     +-c::
>     +--command-only::
>     +   Display help information only for commands.
>     +
>
> First, I do not think a short form is unnecessary; the users are not
> expected to use that form, once they started typing "git help...".
> If we flip the polarity and call it --exclude-guides or something,
> would it make it less ambiguous?
>

Sure.  Since "command" is understood as both Git command
and guide in this context, the name --exclude-guides would describe the
behaviour of that option less ambiguous.  I'll rename it.

>> This breaks "git <concept> --help" while "git help <concept>" still works.
>
> I wouldn't call that a breakage; "git everyday --help" shouldn't
> have worked in the first place.  It did something useful merely by
> accident ;-).
>

OK, I'll call it "doesn't work anymore".

>> diff --git a/git.c b/git.c
>> index 0f1937f..2cd2e06 100644
>> --- a/git.c
>> +++ b/git.c
>> @@ -528,10 +528,23 @@ static void handle_builtin(int argc, const char **argv)
>>       strip_extension(argv);
>>       cmd = argv[0];
>>
>> -     /* Turn "git cmd --help" into "git help cmd" */
>> +     /* Turn "git cmd --help" into "git help --command-only cmd" */
>>       if (argc > 1 && !strcmp(argv[1], "--help")) {
>> +             struct argv_array args;
>> +             int i;
>> +
>>               argv[1] = argv[0];
>>               argv[0] = cmd = "help";
>> +
>> +             argv_array_init(&args);
>> +             for (i = 0; i < argc; i++) {
>> +                     argv_array_push(&args, argv[i]);
>> +                     if (!i)
>> +                             argv_array_push(&args, "--command-only");
>> +             }
>> +
>> +             argc++;
>> +             argv = argv_array_detach(&args);
>>       }
>>
>>       builtin = get_builtin(cmd);
>
> The code does this after it:
>
>     if (builtin)
>                 exit(run_builtin(...));
>
> and returns.  If we didn't get builtin, we risk leaking args.argv
> here, but we assume argv[0] = cmd = "help" is always a builtin,
> which I think is a safe assumption, so the code is OK.  Static
> checkers that are only half intelligent may yell at you for not
> releasing the resources, though.  I wonder if it is worth doing
>
>     static void handle_builtin(int argc, const char **argv)
>     {
>             struct argv_array args = ARGV_ARRAY_INIT;
>             ...
>             if (argc > 1 && !strcmp(argv[1], "--help")) {
>                     ...
>                     argv = args.argv;
>             }
>             builtin = get_builtin(cmd);
>             if (builtin)
>                     exit(run_builtin(...));
>             argv_array_clear(&args);
>     }
>
> to help unconfuse them.
>

I'll do it this way.

Thanks!