added unittest to check for broken btree implementation with unicode

strings as keys

src/BTrees/tests/testBTreesUnicode.py

+import os,sys,unittest
+execfile(os.path.join(sys.path[0],'framework.py'))
+from BTrees.OOBTree import OOBTree
+
+
+class TestBTreesUnicode(unittest.TestCase):
+    """ test unicode"""
+
+    def setUp(self):
+        """ setup an OOBTree with some unicode strings """
+
+        self.s = unicode('dreit\xe4gigen','latin1')
+
+        self.data = [('alien', 284708388), 
+                ('fox', 284708387), 
+                ('future', 284708388), 
+                ('k\xf6nnten', 284708389),
+                ('quick', 284708387), 
+                ('zerst\xf6rt', 284708389), 
+                (unicode('dreit\xe4gigen','latin1'), 284708391)]
+
+        self.tree = OOBTree()
+        for k,v in self.data:   self.tree[k]=v
+
+
+    def test1(self):
+        """ check every item of the tree """
+
+        for k,v in self.data:
+            assert self.tree[k]==v
+
+    def test2(self):
+        """ try to access unicode keys in tree"""
+
+        assert self.data[-1][0]==self.s
+        assert self.tree[self.data[-1][0]] == self.data[-1][1] 
+        assert self.tree[self.s] == self.data[-1][1] 
+
+
+
+def test_suite():
+    return unittest.makeSuite(TestBTreesUnicode,'test')
+
+framework()
+