Re: [PATCH v2 8/8] Use the early config machinery to expand aliases

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Peff,

On Sat, 10 Jun 2017, Jeff King wrote:

> On Thu, Jun 08, 2017 at 09:53:53PM +0200, Johannes Schindelin wrote:
> 
> > @@ -245,36 +201,37 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
> >  
> >  static int handle_alias(int *argcp, const char ***argv)
> >  {
> > +	struct strbuf cdup_dir = STRBUF_INIT;
> >  	int envchanged = 0, ret = 0, saved_errno = errno;
> >  	int count, option_count;
> >  	const char **new_argv;
> >  	const char *alias_command;
> >  	char *alias_string;
> > -	int unused_nongit;
> > -
> > -	save_env_before_alias();
> > -	setup_git_directory_gently(&unused_nongit);
> >  
> >  	alias_command = (*argv)[0];
> > -	alias_string = alias_lookup(alias_command, NULL);
> > +	alias_string = alias_lookup(alias_command, &cdup_dir);
> >  	if (alias_string) {
> >  		if (alias_string[0] == '!') {
> >  			struct child_process child = CHILD_PROCESS_INIT;
> >  
> > +			if (cdup_dir.len)
> > +				setup_git_directory();
> > +
> 
> I'm really confused here. We went to all the trouble to record the
> cdup_dir as part of the alias lookup so that we could make sure to
> chdir() to it.

Right, that was my first idea.

But then the test suite taught me that we set at least GIT_PREFIX and that
tests break (or, in other words, promises Git made earlier) if those
variables are not set.

So as a quick fix, I simply called setup_git_directory() instead of
chdir(cdup_dir.buf).

> I understand why you must use setup_git_directory() and not just a
> chdir(), because the latter sets up variables like GIT_PREFIX and
> GIT_DIR that the shell alias may be depending on.

Exactly.

> But couldn't we just unconditionally do:
> 
>   setup_git_directory_gently();

But of course we can do that! Why on earth did I not think of that...

Will change the code accordingly.

Ciao,
Dscho