[ODBC] Connection failure with invalid connection option "gsslib" for 09.06.0410

Hi all,

When updating the ODBC driver from 09.06.0310 to 09.06.0410 (Yes I
lagged behind one release!), I have noticed a failure when connecting
to a Postgres instance on Windows:
cmd=c:/python27/python check_odbc.py --dsn uninst_std_noimpact_srm
--user test_odbc --pwd passw0rd --port 5444
stdout=Connecting odbc :
DSN=uninst_std_noimpact_srm;Uid=test_odbc;Pwd={passw0rd};

stderr=Traceback (most recent call last):
  File "check_odbc.py", line 111, in main
    check_odbc_connection(conn_str)
  File "check_odbc.py", line 15, in check_odbc_connection
    cnxn = pyodbc.connect(conn_str)
Error: ('08001', '[08001] invalid connection option "gsslib"\n (101)
(SQLDriverConnect)')

check_odbc.py is a simple wrapper on top of pyodbc that attempts a
connection to Postgres on Windows, making sure that the DNS defined is
working correctly. There is nothing fancy in it.

The difference between a failure and a success is only the update of
the ODBC driver, so I'd like to think that it is its fault here ;)

Looking at the code, I think that this diff in dlg_specific.c, coming
from commit 3bad6c8e is at fault:
@@ -790,64 +806,34 @@ copyCommonAttributes(ConnInfo *ci, const char
*attribute, const char *value)
 }
[...]
-void
-getDSNdefaults(ConnInfo *ci)
+static void
+getCiDefaults(ConnInfo *ci)
[...]
-   if (ci->gssauth_use_gssapi < 0)
-       ci->gssauth_use_gssapi = DEFAULT_GSSAUTHUSEGSSAPI;
[...]
+   ci->gssauth_use_gssapi = DEFAULT_GSSAUTHUSEGSSAPI;

This is a problem, because Postgres' libpq may not be compiled with
GSS support, which is the case of my builds, and the existence of the
connection parameter gsslib depends on if Postgres is compiled with
GSS or not. I think also that this is the only problem, the other
libpq parameter whose existence is defined based on compilation is
krbsrvname, and odbc does not handle it. I have only seen this problem
on Windows, because my Linux builds have GSS support, but I have no
doubt that the problem could be seen there as well.

Inoue-san, unfortunately I think that your commit is a fault here.
Thanks,
--
Michael