Bug: special char in dbname is not correctly handled

[kainwen]

Reproduce Steps

First go to Postgres to create a database:

CREATE DATABASE "funny""db'with\\quotes";

Then run the following python code:

In [1]: import pgdb

In [2]: dbname = 'funny\"db\'with\\\\quotes'

In [3]: pgdb.connect(database=dbname)
Out[3]: <pgdb.Connection at 0x10e4f0af0>

In [4]: pgdb.connect(database=dbname, port=5432)
---------------------------------------------------------------------------
InternalError                             Traceback (most recent call last)
<ipython-input-4-ac96bf54cbc4> in <module>
----> 1 pgdb.connect(database=dbname, port=5432)

/Library/Python/3.8/site-packages/pgdb.py in connect(dsn, user, password, host, database, **kwargs)
   1725     # open the connection
   1726     # noinspection PyArgumentList
-> 1727     cnx = _connect(dbname, dbhost, dbport, dbopt, dbuser, dbpasswd)
   1728     return Connection(cnx)
   1729

InternalError: connection to server on socket "/tmp/.s.PGSQL.5432" failed: FATAL:  database "funny"db'with\quotes" does not exist

The strange thing is:

• [3] is OK
• [4] errors out

RCA

[4] pass port=5432 as kwarg, so it will enter this line of code https://github.com/PyGreSQL/PyGreSQL/blob/master/pgdb.py#L1721, and here it only escape dbname when there is space in dbname.

And the dbname variable here is confusing, it will also add port in the string.

[SmartKeyerror]

Maybe some refactoring should be done to the function connect() 🤔

[SmartKeyerror]

@Cito Hi~ Do we have a plan to refactor the function of connect() in pgdb.py? Since the semantics and parameter settings of this function are weird and ambiguous.

For example, the DSN string can't support adding a port to it, cause the format must be 'host:base:user:passwd:opt', we can just add a port to the named parameter host using IP:PORT.

And if we use both DSN and named parameters, there will be mutual coverage. From the current code point of view, named parameters will override the value in DSN.

From my experience, it's better to make the function semantics clearer, just like pymysql.connect:

connection = pymysql.connect(host='localhost',
                             user='user',
                             password='passwd',
                             database='db',
                             port='port')

[Cito]

Will look into this in the next major version which will also allow us to introduce some breaking changes.