We weren't computing the virtual root correctly in a corner case.

2 files changed, 74 insertions, 42 deletions

diff --git a/repoze/bfg/tests/test_traversal.py b/repoze/bfg/tests/test_traversal.py
index da52ab968..7d24cb9bc 100644
--- a/repoze/bfg/tests/test_traversal.py
+++ b/repoze/bfg/tests/test_traversal.py
@@ -88,6 +88,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], policy.root)
         self.assertEqual(result['virtual_root'], policy.root)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -99,6 +100,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], 'foo')
         self.assertEqual(result['subpath'], ('bar',))
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], policy.root)
         self.assertEqual(result['virtual_root'], policy.root)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -111,6 +113,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], root)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -124,6 +127,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], 'bar')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], (u'foo',))
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], root)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -137,6 +141,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], 'bar')
         self.assertEqual(result['subpath'], ('baz', 'buz'))
         self.assertEqual(result['traversed'], (u'foo',))
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], root)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -150,38 +155,41 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], 'foo')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], root)
         self.assertEqual(result['virtual_root_path'], ())
 
     def test_call_with_vh_root(self):
         environ = self._getEnviron(PATH_INFO='/baz',
                                    HTTP_X_VHM_ROOT='/foo/bar')
-        baz = DummyContext()
-        bar = DummyContext(baz)
-        foo = DummyContext(bar)
-        root = DummyContext(foo)
+        baz = DummyContext(None, 'baz')
+        bar = DummyContext(baz, 'bar')
+        foo = DummyContext(bar, 'foo')
+        root = DummyContext(foo, 'root')
         policy = self._makeOne(root)
         result = policy(environ)
         self.assertEqual(result['context'], baz)
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], (u'foo', u'bar', u'baz'))
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], bar)
         self.assertEqual(result['virtual_root_path'], (u'foo', u'bar'))
 
     def test_call_with_vh_root2(self):
         environ = self._getEnviron(PATH_INFO='/bar/baz',
                                    HTTP_X_VHM_ROOT='/foo')
-        baz = DummyContext()
-        bar = DummyContext(baz)
-        foo = DummyContext(bar)
-        root = DummyContext(foo)
+        baz = DummyContext(None, 'baz')
+        bar = DummyContext(baz, 'bar')
+        foo = DummyContext(bar, 'foo')
+        root = DummyContext(foo, 'root')
         policy = self._makeOne(root)
         result = policy(environ)
         self.assertEqual(result['context'], baz)
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], (u'foo', u'bar', u'baz'))
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], foo)
         self.assertEqual(result['virtual_root_path'], (u'foo',))
 
@@ -198,9 +206,27 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], (u'foo', u'bar', u'baz'))
+        self.assertEqual(result['root'], root)
         self.assertEqual(result['virtual_root'], root)
         self.assertEqual(result['virtual_root_path'], ())
 
+    def test_call_with_vh_root4(self):
+        environ = self._getEnviron(PATH_INFO='/',
+                                   HTTP_X_VHM_ROOT='/foo/bar/baz')
+        baz = DummyContext(None, 'baz')
+        bar = DummyContext(baz, 'bar')
+        foo = DummyContext(bar, 'foo')
+        root = DummyContext(foo, 'root')
+        policy = self._makeOne(root)
+        result = policy(environ)
+        self.assertEqual(result['context'], baz)
+        self.assertEqual(result['view_name'], '')
+        self.assertEqual(result['subpath'], ())
+        self.assertEqual(result['traversed'], (u'foo', u'bar', u'baz'))
+        self.assertEqual(result['root'], root)
+        self.assertEqual(result['virtual_root'], baz)
+        self.assertEqual(result['virtual_root_path'], (u'foo', u'bar', u'baz'))
+
     def test_call_with_vh_root_path_root(self):
         policy = self._makeOne(None)
         environ = self._getEnviron(HTTP_X_VHM_ROOT='/',
@@ -210,6 +236,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], policy.root)
         self.assertEqual(result['virtual_root'], policy.root)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -239,6 +266,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ())
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], model)
         self.assertEqual(result['virtual_root'], model)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -251,6 +279,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], '')
         self.assertEqual(result['subpath'], ('a', 'b','c'))
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], model)
         self.assertEqual(result['virtual_root'], model)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -263,6 +292,7 @@ class ModelGraphTraverserTests(unittest.TestCase):
         self.assertEqual(result['view_name'], 'foo')
         self.assertEqual(result['subpath'], ('bar',))
         self.assertEqual(result['traversed'], ())
+        self.assertEqual(result['root'], model)
         self.assertEqual(result['virtual_root'], model)
         self.assertEqual(result['virtual_root_path'], ())
 
@@ -917,15 +947,18 @@ def make_traverser(result):
         
 class DummyContext(object):
     __parent__ = None
-    __name__ = None
-    def __init__(self, next=None):
+    def __init__(self, next=None, name=None):
         self.next = next
+        self.__name__ = name
         
     def __getitem__(self, name):
         if self.next is None:
             raise KeyError, name
         return self.next
 
+    def __repr__(self):
+        return '<DummyContext with name %s at id %s>'%(self.__name__, id(self))
+
 class DummyRequest:
     application_url = 'http://example.com:5432' # app_url never ends with slash
     def __init__(self, environ=None):
diff --git a/repoze/bfg/traversal.py b/repoze/bfg/traversal.py
index 59ad9115d..2b9a0e611 100644
--- a/repoze/bfg/traversal.py
+++ b/repoze/bfg/traversal.py
@@ -502,69 +502,68 @@ class ModelGraphTraverser(object):
             # this request did not match a Routes route
             subpath = ()
             try:
-                path = environ['PATH_INFO']
+                path = environ['PATH_INFO'] or '/'
             except KeyError:
                 path = '/'
 
         try:
-            vroot_path_string = environ[VH_ROOT_KEY]
+            vroot_path = environ[VH_ROOT_KEY]
         except KeyError:
-            vroot_path = ()
-            vroot_idx = 0
+            vroot_tuple = ()
+            vpath = path
+            vroot_idx = -1
         else:
-            vroot_path = traversal_path(vroot_path_string)
-            vroot_idx = len(vroot_path)
-            path = vroot_path_string + path
+            vroot_tuple = traversal_path(vroot_path)
+            vpath = vroot_path + path
+            vroot_idx = len(vroot_tuple) -1
 
         ob = vroot = self.root
 
-        if (not path) or path == '/':
-            # save a call to traversal_path if we know it's going to return
-            # the empty tuple
-            path = ()
+        if vpath == '/' or (not vpath):
+            # prevent a call to traversal_path if we know it's going
+            # to return the empty tuple
+            vpath_tuple = ()
         else:
-            path = traversal_path(path)
-
-            # in case you're wondering, we do dead reckoning here instead
-            # of pushing and popping temporary lists for speed purposes
-
-            i = 1
-            j = vroot_idx
-
-            for segment in path:
+            # we do dead reckoning here via tuple slicing instead of
+            # pushing and popping temporary lists for speed purposes
+            # and this hurts readability; apologies
+            i = 0
+            vpath_tuple = traversal_path(vpath)
+            for segment in vpath_tuple:
                 if segment[:2] =='@@':
                     return dict(context=ob, view_name=segment[2:],
-                                subpath=path[i:], traversed=path[:j],
+                                subpath=vpath_tuple[i+1:],
+                                traversed=vpath_tuple[:vroot_idx+i+1],
                                 virtual_root=vroot,
-                                virtual_root_path=vroot_path,
+                                virtual_root_path=vroot_tuple,
                                 root=self.root)
                 try:
                     getitem = ob.__getitem__
                 except AttributeError:
                     return dict(context=ob, view_name=segment,
-                                subpath=path[i:], traversed=path[:j],
+                                subpath=vpath_tuple[i+1:],
+                                traversed=vpath_tuple[:vroot_idx+i+1],
                                 virtual_root=vroot,
-                                virtual_root_path=vroot_path,
+                                virtual_root_path=vroot_tuple,
                                 root=self.root)
 
                 try:
                     next = getitem(segment)
                 except KeyError:
                     return dict(context=ob, view_name=segment,
-                                subpath=path[i:], traversed=path[:j],
+                                subpath=vpath_tuple[i+1:],
+                                traversed=vpath_tuple[:vroot_idx+i+1],
                                 virtual_root=vroot,
-                                virtual_root_path=vroot_path,
+                                virtual_root_path=vroot_tuple,
                                 root=self.root)
-
-                if vroot_idx == i-1:
-                    vroot = ob
+                if i == vroot_idx: 
+                    vroot = next
                 ob = next
                 i += 1
-                j += 1
 
         return dict(context=ob, view_name=u'', subpath=subpath,
-                    traversed=path, virtual_root=vroot,
-                    virtual_root_path=vroot_path, root=self.root)
+                    traversed=vpath_tuple, virtual_root=vroot,
+                    virtual_root_path=vroot_tuple, root=self.root)
 
 class TraversalContextURL(object):
     """ The IContextURL adapter used to generate URLs for a context