RE: About limitation characters in ECPG's connection string

Hi Tom,

> We put in a change about that last month:
>
> https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=756349c87

Thank you for accepting my claim and updating document!
And sorry for not checking the development version of the document.

> > Note that this parameter does not allow the symbols with special meaning of
> > the URI parts, e.g. "&" and "?".
>
> Hm, I agree that the options part doesn't accept "&", but I don't see
> anything preventing use of a "?" there.

I have checked additional pattern about this limitation, and I found also "?" is not able to use in below case.
user : tst
password : test?pass
connection string: tcp:postgresql://localhost/egashira?user=tst&password=test?pss

This seems to be caused by ECPGconnect's parsing routine.
https://github.com/postgres/postgres/blob/master/src/interfaces/ecpg/ecpglib/connect.c#L371

----
if (strncmp(dbname + offset, "postgresql://", strlen("postgresql://")) == 0)
{

/*------
* new style:
* <tcp|unix>:postgresql://server[:port|:/unixsocket/path:]
* [/db-name][?options]
*------
*/
offset += strlen("postgresql://");

tmp = strrchr(dbname + offset, '?');
if (tmp != NULL) /* options given */
{
options = ecpg_strdup(tmp + 1, lineno);
*tmp = '\0';
}
----

In "tcp:postgresql://" style connection string, ECPGconnect searches for "?" from the end of the connection string to extract options part.
If "?" is in options string part (e.g. as a password value) , the extracting will be failed.

Regards.
Yusuke Egashira.

-----Original Message-----
From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
Sent: Wednesday, September 18, 2019 12:55 AM
To: Egashira, Yusuke/江頭 勇佑 <egashira(dot)yusuke(at)jp(dot)fujitsu(dot)com>
Cc: pgsql-docs(at)lists(dot)postgresql(dot)org
Subject: Re: About limitation characters in ECPG's connection string

PG Doc comments form <noreply(at)postgresql(dot)org> writes:
> Please add the note about the limitation characters in connection string.
> For example, I think that below explanation should be in the Parameter
> section of connection_target.

We put in a change about that last month:

https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=756349c87

Although that hasn't yet propagated to any released branches,
you can see it in the "devel" version of that documentation page:

https://www.postgresql.org/docs/devel/ecpg-connect.html#ECPG-CONNECTING

> Note that this parameter does not allow the symbols with special meaning of
> the URI parts, e.g. "&" and "?".

Hm, I agree that the options part doesn't accept "&", but I don't see
anything preventing use of a "?" there.

regards, tom lane