fix(db): Make using pg_service work again. When I did the merge of schema support I broke pg_service.conf support by replacing get_database_name with db_schema_split. This commit fixes it. Also this commit returns the schema if one is specified in pg_service.conf. back_postgresql.py: Replace calls to db_schema_split() with get_database_schema_names() (new name for get_database_name()). Rename db_schema_split to _db_schema_split. It now returns a tuple (dbname, schema) rather than a list. It is used only by get_database_schema_names() which also returns tuples. get_database_schema_names() can also get schema info for the service (if present) as specified by pg_service.conf. Add get_database_user() to get the user from either RDBMS_USER or pg_service.conf. (User needed for creating schema, so not needed before schema patch. import re at the top of file and remove lower import. Remove some schema code from db_command as it's not needed. The database conection is done to either postgresql or template1 existing databases. This command never connects to the roundp specified db. test/test_postgresql.py: Reorganize top level imports, add import os. Replace import of db_schema_split with get_database_schema_names. Also replace calls to db_schema_split. Create new Opener for the service file. Set PGSERVICEFILE to point to test/pg_service.conf. Add three new classes to test Service: 1) using regular db 2) using schema within db 3) Unable to parse schema name from pg_service.conf. The last doesn't need a db. Number 1 and 2 reuse the tests in ROTest to verify db connectivity. test/pg_service.conf: three service connections for: db only, db and schema, and incorrectly specified schema test cases. doc/upgrading.txt: updated to current status. Included example schema definition in service file.

"""
In Python 3, sometimes TAL "python:" expressions that refer to
variables but not all variables are recognized. That is in Python 2.7
all variables used in a TAL "python:" expression are recognized as
references. In Python 3.5 (perhaps earlier), some TAL "python:"
expressions refer to variables but the reference generates an error
like this:

<class 'NameError'>: name 'some_tal_variable' is not defined

even when the variable is defined. Output after this message lists the
variable and its value.
"""

import unittest

from roundup.cgi.PageTemplates.PythonExpr import PythonExpr as PythonExprClass

class ExprTest(unittest.TestCase):
    def testExpr(self):
        expr = '[x for x in context.assignedto ' \
               'if x.realname not in user_realnames]'
        pe = PythonExprClass('test', expr, None)
        # Looking at the expression, only context and user_realnames are
        # external variables. The names assignedto and realname are members,
        # and x is local.
        required_names = ['context', 'user_realnames']
        got_names = pe._f_varnames
        for required_name in required_names:
            self.assertIn(required_name, got_names)