Port idlib to Python 3, making its behavior consistent across Python 2 and 3.

src/allmydata/test/test_util.py

@@ -33,7 +33,9 @@ if six.PY3:
 
 class IDLib(unittest.TestCase):
     def test_nodeid_b2a(self):
-        self.failUnlessEqual(idlib.nodeid_b2a(b"\x00"*20), "a"*32)
+        result = idlib.nodeid_b2a(b"\x00"*20)
+        self.assertEqual(result, "a"*32)
+        self.assertIsInstance(result, str)
 
 
 class MyList(list):

src/allmydata/util/_python3.py

@@ -94,6 +94,7 @@ PORTED_MODULES = [
     "allmydata.util.happinessutil",
     "allmydata.util.hashutil",
     "allmydata.util.humanreadable",
+    "allmydata.util.idlib",
     "allmydata.util.iputil",
     "allmydata.util.jsonbytes",
     "allmydata.util.log",

src/allmydata/util/idlib.py

@@ -1,9 +1,29 @@
+"""
+Ported to Python 3.
+"""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
 
+from future.utils import PY2
+if PY2:
+    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
 
+from six import ensure_text
 from foolscap import base32
+
+
 def nodeid_b2a(nodeid):
-    # we display nodeids using the same base32 alphabet that Foolscap uses
+    """
-    return base32.encode(nodeid)
+    We display nodeids using the same base32 alphabet that Foolscap uses.
+
+    Returns a Unicode string.
+    """
+    return ensure_text(base32.encode(nodeid))
 
 def shortnodeid_b2a(nodeid):
+    """
+    Short version of nodeid_b2a() output, Unicode string.
+    """
     return nodeid_b2a(nodeid)[:8]