Re: [PATCH v5 2/2] hooks: allow input from stdin for commit-related hooks

[Junio C Hamano <gitster@pobox.com>]

"Orgad Shaneh via GitGitGadget" <gitgitgadget@gmail.com> writes:

> It's important to note that the hook author should be aware that stdin
> is not always applicable. For example, when running from IDE. This can
> be checked by isatty on stdin. The hooks should handle cases of closed
> input, and possibly fall-back to GUI input, or have sane defaults with
> a message to the user on this case.

I think this point was already brought up in the review on previous
rounds, but when the hook needs to check the standard input anyway,
it probably is a better design to close and have the hook open tty
if needed, isn't it?  I do not recall I saw a satisfactory answer to
that question.

> Allow stdin only for commit-related hooks. Some of the other hooks pass
> their own input to the hook, so don't change them.
>
> Note: If pre-commit reads from stdin, and git commit is executed with
> -F - (read message from stdin), stdin cannot be passed to the hook,
> since it will consume it before reaching the point where it is read for
> the commit message.

It is unclear what that Note is trying to achieve.  Is it describing
a known-bug in this implementation (if so, we'd probably need to
update the documentation to mention this known regression)?  Is it
describing a reason why certain part of patch was done in a certain
way that is not described in this message (e.g. when -F option is in
effect the standard input stream is closed when invoking a hook)?

Thanks.