Re: Alternative approach to the git config NULL value checking patches..

> Linus Torvalds <torvalds@linux-foundation.org> writes:
> 
> > It may be a bit odd, but it automatically means that codepaths that simply 
> > don't want to care about the subtle difference between "true" and "empty" 
> > will just automatically work, because to them the two cases will look 
> > identical, because the strings will compare the same - they have the same 
> > data, just different addresses.
> 
> I should have mentioned the reason why I did not suggest doing
> it this way in my [Janitor] message.
> 
> It is not "suttle difference between true and empty".  Empty
> means false, and with this approach, it switches the meaning of
> valueless form of config to quite the opposite.
> 
> In addition to fixing existing breakages, a piece of code that
> knew NULL is true and empty is false and coded accordingly, i.e.
> 
> 	if (!value)
>         	Ah we have true;
> 	else if (!*value)
>         	Ok this is false;
> 	else if (!strcmp(value, "something special")
>         	Ok, this is not bool but special;
> 	else
>         	return git_config_bool(var, value);
> 
> will now need to be changed to:
> 
> 	if (value == config_true)
>         	Ah we have true;
> 	else if (!*value)
>         	Ok this is false;
> 	else if (!strcmp(value, "something special")
>         	Ok, this is not bool but special;
> 	else
>         	return git_config_bool(var, value);

> if you do this.  And the code that was already broken:
> 
> 	if (!strcmp(value, "somevalue")
> 		Ok let's use somevalue;
> 	else if (!strcmp(value, "someothervalue")
> 		Ok let's use someothervalue;
> 	else
>         	die("oops we do not understand '%s'", value);
> 
> still need to be fixed to:
> 
> 	if (value == config_true)
>         	die("oops '%s' is not a bool", var);
> 	else if (!strcmp(value, "somevalue")
> 		Ok let's use somevalue;
> 	else if (!strcmp(value, "someothervalue")
> 		Ok let's use someothervalue;
> 	else
>         	die("oops we do not understand '%s'", value);