Request local objects now fail properly with a RuntimeError. This fixes pallets#105

Author: mitsuhiko

CHANGES

@@ -11,6 +11,8 @@ Release date to be announced, codename to be selected
 - Added :meth:`~flask.Flask.make_default_options_response`
   which can be used by subclasses to alter the default
   behaviour for `OPTIONS` responses.
+- Unbound locals now raise a proper :exc:`RuntimeError` instead
+  of an :exc:`AttributeError`.
 
 Version 0.6.1
 -------------

docs/upgrading.rst

@@ -19,6 +19,14 @@ installation, make sure to pass it the ``-U`` parameter::
 
     $ easy_install -U Flask
 
+Version 0.7
+-----------
+
+Due to a bug in earlier implementations the request local proxies now
+raise a :exc:`RuntimeError` instead of an :exc:`AttributeError` when they
+are unbound.  If you cought these exceptions with :exc:`AttributeError`
+before, you should catch them with :exc:`RuntimeError` now.
+
 Version 0.6
 -----------
 

flask/globals.py

@@ -10,11 +10,18 @@
     :license: BSD, see LICENSE for more details.
 """
 
+from functools import partial
 from werkzeug import LocalStack, LocalProxy
 
+def _lookup_object(name):
+    top = _request_ctx_stack.top
+    if top is None:
+        raise RuntimeError('working outside of request context')
+    return getattr(top, name)
+
 # context locals
 _request_ctx_stack = LocalStack()
-current_app = LocalProxy(lambda: _request_ctx_stack.top.app)
-request = LocalProxy(lambda: _request_ctx_stack.top.request)
-session = LocalProxy(lambda: _request_ctx_stack.top.session)
-g = LocalProxy(lambda: _request_ctx_stack.top.g)
+current_app = LocalProxy(partial(_lookup_object, 'app'))
+request = LocalProxy(partial(_lookup_object, 'request'))
+session = LocalProxy(partial(_lookup_object, 'session'))
+g = LocalProxy(partial(_lookup_object, 'g'))

tests/flask_tests.py

@@ -72,7 +72,7 @@ def index():
         ctx.pop()
         try:
             index()
-        except AttributeError:
+        except RuntimeError:
             pass
         else:
             assert 0, 'expected runtime error'
@@ -469,6 +469,10 @@ def test():
         else:
             assert "Expected ValueError"
 
+    def test_request_locals(self):
+        self.assertEqual(repr(flask.g), '<LocalProxy unbound>')
+        self.assertFalse(flask.g)
+
 
 class JSONTestCase(unittest.TestCase):