About limitation characters in ECPG's connection string

PG Doc comments form <noreply@postgresql.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&amp;a=commitdiff&amp;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

Hi Tom,

We put in a change about that last month:

https://git.postgresql.org/gitweb/?p=postgresql.git&amp;a=commitdiff&amp;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@sss.pgh.pa.us]
Sent: Wednesday, September 18, 2019 12:55 AM
To: Egashira, Yusuke/江頭 勇佑 <egashira.yusuke@jp.fujitsu.com>
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: About limitation characters in ECPG's connection string

PG Doc comments form <noreply@postgresql.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&amp;a=commitdiff&amp;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