Cast some data read from dump files to str, to prevent unicode promotion.

This fixes a bug that caused a traceback when de-serialized requests were
replayed. Also adds unit tests for the problem.

libmproxy/proxy.py

@@ -198,11 +198,11 @@ class Request(controller.Msg):
     def from_state(klass, state):
         return klass(
             ClientConnect.from_state(state["client_conn"]),
-            state["host"],
+            str(state["host"]),
             state["port"],
-            state["scheme"],
-            state["method"],
-            state["path"],
+            str(state["scheme"]),
+            str(state["method"]),
+            str(state["path"]),
             utils.Headers.from_state(state["headers"]),
             base64.decodestring(state["content"]),
             state["timestamp"]
@@ -353,7 +353,7 @@ class Response(controller.Msg):
         return klass(
             request,
             state["code"],
-            state["msg"],
+            str(state["msg"]),
             utils.Headers.from_state(state["headers"]),
             base64.decodestring(state["content"]),
             state["timestamp"],

test/test_flow.py

@@ -385,6 +385,7 @@ class uSerialize(libpry.AutoTree):
     def test_roundtrip(self):
         sio = StringIO()
         f = tutils.tflow()
+        f.request.content = "".join(chr(i) for i in range(255))
         w = flow.FlowWriter(sio)
         w.add(f)
 
@@ -392,7 +393,10 @@ class uSerialize(libpry.AutoTree):
         r = flow.FlowReader(sio)
         l = list(r.stream())
         assert len(l) == 1
-        assert l[0] == f
+
+        f2 = l[0]
+        assert f2 == f
+        assert f2.request.assemble() == f.request.assemble()
 
     def test_load_flows(self):
         r = self._treader()