The field_exists() method bug in Postgres

[eluser]gokure[/eluser]
Hi!

When I use field_exists() method (in the DB_driver.php file) check table field is exist or not, but it's always returns FALSE. I used Postgres 8.3.6 database.
I check the code and found in the field_exists() method call a private method _list_columns() (in the postgres/postgres_driver.php) and that have a wrapped parameter, I print _list_columns() returns value, it's looks like below:

Code:

SELECT column_name FROM information_schema.columns WHERE table_name ='"users"'

the users is table column, but not have the quotes.

[eluser]gokure[/eluser]
I found this bug since the postgres_driver::_escape_identifiers() method, it's $_escape_char value is '"', and ... it's my all ability =(.