RE: parse mistake in ecpg connect string

Dear Wang, Tom

> I think add the bison rule is a little difficult because in PG13 windows can also support unix-socket,
> In your patch:
> > dir_name: '/' dir_name{ $$ = make2_str(mm_strdup("/"), $2); }
> > | ecpg_ident{ $$ = $1; }
> >;
> Windows will remains wrong(I'm not sure ecpg on windows can use unix socket connection).
>
> And if we add the rules in bison files, both ecpg and ecpglib will both parse the host in different ways.
> Ecpg parse the host by bison rules, and ecpglib parse the host by splitting the connect string use char '@' or char '='.
> I think it's not a good action.
>
> But If we add some description on docs, these problem can be solved in an easy way.
> Therefore, I prefer to add some description on docs.

I didn't care about the windows environment.
Somewhat WIN32 directive can be used for switching code, but I agree your claims.

> I think we can add some description on docs, but I don't have ability to write description in English,
> Can someone help me write a description?

I'm also not a native English speaker, but I put a draft.
Please review it and combine them if it's OK.

> Should we allow "::1" here as well? On the other hand, colons are
> already overloaded in this syntax, so maybe allowing them in the
> host part is a bad idea.

I have no idea how to fix it now, so I added notice that IPv6 should not be used
in the host part...

Best Regards,
Hayato Kuroda
FUJITSU LIMITED