Maximum recursion depth when mysql connection string has an invalid connection parameter

[Jun Omae]

Maximum recursion depth raises due to accessing self.log attribute before setting the self.log attribute. It seems that this issue is introduced in r10407…

trunk

$ TRAC_TEST_DB_URI='mysql://tracuser:password@127.0.0.1/trac_utf8mb4?unknown=value' ~/venv/py39/bin/python
Python 3.9.16 (main, Dec  7 2022, 01:11:51)
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from trac.test import EnvironmentStub, get_dburi
>>> get_dburi()
'mysql://tracuser:password@127.0.0.1/trac_utf8mb4?unknown=value'
>>> env = EnvironmentStub()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/jun66j5/src/tracdev/git/trac/core.py", line 142, in __call__
    self.__init__(*args, **kwargs)
  File "/home/jun66j5/src/tracdev/git/trac/test.py", line 392, in __init__
    self.reset_db(default_data)
  File "/home/jun66j5/src/tracdev/git/trac/test.py", line 443, in reset_db
    dbm.init_db()
  File "/home/jun66j5/src/tracdev/git/trac/db/api.py", line 283, in init_db
    connector.init_db(**args)
  File "/home/jun66j5/src/tracdev/git/trac/db/mysql_backend.py", line 131, in init_db
    cnx = self.get_connection(path, log, user, password, host, port,
  File "/home/jun66j5/src/tracdev/git/trac/db/mysql_backend.py", line 117, in get_connection
    cnx = MySQLConnection(path, log, user, password, host, port, params)
  File "/home/jun66j5/src/tracdev/git/trac/db/mysql_backend.py", line 401, in __init__
    self.log.warning("Invalid connection string parameter '%s'",
  File "/home/jun66j5/src/tracdev/git/trac/db/util.py", line 114, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  File "/home/jun66j5/src/tracdev/git/trac/db/util.py", line 114, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  File "/home/jun66j5/src/tracdev/git/trac/db/util.py", line 114, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  [Previous line repeated 987 more times]
RecursionError: maximum recursion depth exceeded

1.0-stable

$ TRAC_TEST_DB_URI='mysql://tracuser:password@127.0.0.1/trac_utf8mb4?unknown=value' ~/venv/py27/bin/python    Python 2.7.18 (default, Jul  1 2022, 12:27:04)
[GCC 9.4.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from trac.test import EnvironmentStub, get_dburi
>>> get_dburi()
'mysql://tracuser:password@127.0.0.1/trac_utf8mb4?unknown=value'
>>> env = EnvironmentStub()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "trac/core.py", line 124, in __call__
    self.__init__(*args, **kwargs)
  File "trac/test.py", line 432, in __init__
    self.reset_db(default_data)
  File "trac/test.py", line 479, in reset_db
    self.global_databasemanager.init_db()
  File "trac/db/api.py", line 253, in init_db
    connector.init_db(**args)
  File "trac/db/mysql_backend.py", line 123, in init_db
    params)
  File "trac/db/mysql_backend.py", line 104, in get_connection
    cnx = MySQLConnection(path, log, user, password, host, port, params)
  File "trac/db/mysql_backend.py", line 375, in __init__
    self.log.warning("Invalid connection string parameter '%s'",
  File "trac/db/util.py", line 113, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  File "trac/db/util.py", line 113, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  File "trac/db/util.py", line 113, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  ...
  File "trac/db/util.py", line 113, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
  File "trac/db/util.py", line 113, in __getattr__
    if self.readonly and name in ('commit', 'rollback'):
RuntimeError: maximum recursion depth exceeded while calling a Python object

Patch to trunk

trac/db/mysql_backend.py

@@ -395 +395 @@
                 if value in ('utf8', 'utf8mb4'):
                     opts[name] = value
                 else:
-                    self.log.warning("Invalid connection string parameter "
-                                     "'%s=%s'", name, value)
+                    log.warning("Invalid connection string parameter '%s=%s'",
+                                name, value)
             else:
-                self.log.warning("Invalid connection string parameter '%s'",
-                                 name)
+                log.warning("Invalid connection string parameter '%s'", name)
         cnx = pymysql.connect(db=path, user=user, passwd=password, host=host,
                               port=port, **opts)
         cursor = cnx.cursor()

[Jun Omae]

Fixed and merged in [17636-17641].