Re: [RFC PATCH] Allow aliases that include other aliases
- Date: Tue, 4 Sep 2018 16:11:16 -0400
- From: Jeff King <peff@xxxxxxxx>
- Subject: Re: [RFC PATCH] Allow aliases that include other aliases
On Tue, Sep 04, 2018 at 10:55:35AM -0700, Junio C Hamano wrote:
> Tim Schumacher <timschumi@xxxxxx> writes:
> > I submitted this as RFC because I'm not sure whether disallowing
> > nested aliases was an intentional design choice. The done_alias
> > check implies that disallowing is intended, but the direct
> > recursion check for aliases that call themselves opposes that.
> "direct recursion check for aliases"? I am not sure what you mean
> by that, but anyway.
> If I recall correctly, it is intended that we disallow run_argv()
> doing handle_alias() twice (or more). But the ultimate objective is
> to forbid infinite loops, "git foo" expanding to "git bar" which in
> turn expanding back to "git foo", and the current "do not expand
> alias to another" is a simple but too strict implementation. As
> long as a replacement implementation still forbids infinite loops
> with reasonable cost and complexity, I do not think we would mind
> such an improvement to allow alias expanding to another alias.
I agree that this could be looser, if all we care about is infinite
loops. But given the issues we've had with aliases and the startup
sequence, I also would not be surprised if there is some weird hidden
effect if we call handle_alias() more than once.
That's not a reason not to pursue this, but just one more thing to look
As an aside, you can still do this:
$ git config alias.foo '!git bar'
$ git config alias.bar '!git foo'
$ git foo
[boy, my CPU fan is really spinning]
I don't know how much effort we actually need to put into people not
shooting themselves in the foot, since we can't cover all of the cases
anyway (and in a non-infinite configuration, that's another solution for
Tim's original problem).