database connection error triggers generic 500 error when ATOMIC_REQUESTS

[tisdall]

Something seems to have broken PR #87 . When I hit watchman and a database isn't working, it triggers a generic error before reaching watchman and then I get emailed a stacktrace. I'm using Django 1.11.20. If I comment out ATOMIC_REQUESTS in DATABASES then it works properly.

@ulope was the original author of the patch, so maybe they have some insight

It seems like it checks for autocommit and that then calls ensure_connection which then raises an error.

Traceback:

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/exception.py" in inner
  41.             response = get_response(request)

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in _get_response
  187.                 response = self.process_exception_by_middleware(e, request)

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in _get_response
  185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/usr/local/lib/python2.7/site-packages/django/utils/decorators.py" in inner
  184.                 with self:

File "/usr/local/lib/python2.7/site-packages/django/db/transaction.py" in __enter__
  158.             if not connection.get_autocommit():

File "/usr/local/lib/python2.7/site-packages/django/db/backends/base/base.py" in get_autocommit
  385.         self.ensure_connection()

File "/usr/local/lib/python2.7/site-packages/django/db/backends/base/base.py" in ensure_connection
  213.                 self.connect()

File "/usr/local/lib/python2.7/site-packages/django/db/utils.py" in __exit__
  94.                 six.reraise(dj_exc_type, dj_exc_value, traceback)

File "/usr/local/lib/python2.7/site-packages/django/db/backends/base/base.py" in ensure_connection
  213.                 self.connect()

File "/usr/local/lib/python2.7/site-packages/django/db/backends/base/base.py" in connect
  189.         self.connection = self.get_new_connection(conn_params)

File "/usr/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py" in get_new_connection
  274.         conn = Database.connect(**conn_params)

File "/usr/local/lib/python2.7/site-packages/MySQLdb/__init__.py" in Connect
  85.     return Connection(*args, **kwargs)

File "/usr/local/lib/python2.7/site-packages/MySQLdb/connections.py" in __init__
  204.         super(Connection, self).__init__(*args, **kwargs2)

Exception Type: OperationalError at /watchman/dashboard/
Exception Value: (2003, 'Can\'t connect to MySQL server on \'127.0.0.1\' (111 "Connection refused")')