Minor bugfix when applying 'prettystr' to a voevent packet-root.

The prettystr command applies the deannotate / cleanup_namespaces routines,
this conflicts with the namespace mangling we temporarily apply to
make objectify work nicely with VOEvents.

The fix is simple - we simply take a copy of the passed datastructure,
then deannotate and prettyprint that.

setup.py

@@ -4,7 +4,7 @@
 
 setup(
     name="voevent-parse",
-    version="0.9.3",
+    version="0.9.4",
     packages=['voeventparse', 'voeventparse.tests', 'voeventparse.tests.resources'],
     package_data={'voeventparse':['tests/resources/*.xml']},
     description="Convenience routines for parsing and manipulation of "

tox.ini

@@ -15,5 +15,6 @@ deps =
 deps=
     sphinx
 commands=
+    pip install -r documentation/requirements.txt
     pip install -e .
     sphinx-build -W -b html -d {envtmpdir}/doctrees documentation/source  {envtmpdir}/html

voeventparse/convenience.py

@@ -6,6 +6,7 @@
 from collections import OrderedDict
 from voeventparse.misc import (Param, Group, Reference, Inference, Position2D,
                                Citation)
+from copy import deepcopy
 
 
 
@@ -139,6 +140,7 @@ def prettystr(subtree):
     Returns:
         string: Prettyprinted string representation of the raw XML.
     """
+    subtree = deepcopy(subtree)
     lxml.objectify.deannotate(subtree)
     lxml.etree.cleanup_namespaces(subtree)
     return lxml.etree.tostring(subtree, pretty_print=True)

voeventparse/tests/test_voeventparse.py

@@ -360,3 +360,18 @@ def test_pull_isotime(self):
 
         null_result = vp.pull_isotime(self.blank)
         self.assertIsNone(null_result)
+
+class TestPrettyStr(TestCase):
+    def setUp(self):
+        with open(datapaths.swift_bat_grb_pos_v2, 'rb') as f:
+            self.swift_grb_v2_packet = vp.load(f)
+    def test_for_packet_mangling(self):
+        """
+        Check that applying prettystr to a packet does not change it.
+        """
+        self.assertTrue(vp.valid_as_v2_0(self.swift_grb_v2_packet))
+        before = vp.dumps(self.swift_grb_v2_packet)
+        vp.prettystr(self.swift_grb_v2_packet)
+        self.assertTrue(vp.valid_as_v2_0(self.swift_grb_v2_packet))
+        after = vp.dumps(self.swift_grb_v2_packet)
+        self.assertEqual(before,after)