Make tests pass for catching exceptions.

May now use sys.excepthook to catch exceptions
from threaded handlers.

sleekxmpp/stanza/rootstanza.py

@@ -64,7 +64,7 @@ class RootStanza(StanzaBase):
             log.exception('Error handling {%s}%s stanza' %
                           (self.namespace, self.name))
             # Finally raise the exception, so it can be handled (or not)
-            # at a higher level
+            # at a higher level by using sys.excepthook.
             raise e
 
 register_stanza_plugin(RootStanza, Error)

sleekxmpp/xmlstream/xmlstream.py

@@ -682,6 +682,7 @@ class XMLStream(object):
                         Event handlers and the send queue will be threaded
                         regardless of this parameter's value.
         """
+        self._thread_excepthook()
         self.scheduler.process(threaded=True)
 
         def start_thread(name, target):
@@ -954,3 +955,26 @@ class XMLStream(object):
             self.disconnect()
             self.event_queue.put(('quit', None, None))
             return
+
+    def _thread_excepthook(self):
+        """
+        If a threaded event handler raises an exception, there is no way to
+        catch it except with an excepthook. Currently, each thread has its own
+        excepthook, but ideally we could use the main sys.excepthook.
+
+        Modifies threading.Thread to use sys.excepthook when an exception
+        is not caught.
+        """
+        init_old = threading.Thread.__init__
+        def init(self, *args, **kwargs):
+            init_old(self, *args, **kwargs)
+            run_old = self.run
+            def run_with_except_hook(*args, **kw):
+                try:
+                    run_old(*args, **kw)
+                except (KeyboardInterrupt, SystemExit):
+                    raise
+                except:
+                    sys.excepthook(*sys.exc_info())
+            self.run = run_with_except_hook
+        threading.Thread.__init__ = init

tests/test_stream_exceptions.py

@@ -10,6 +10,7 @@ class TestStreamExceptions(SleekTest):
     """
 
     def tearDown(self):
+        sys.excepthook = sys.__excepthook__
         self.stream_close()
 
     def testXMPPErrorException(self):
@@ -78,9 +79,16 @@ class TestStreamExceptions(SleekTest):
     def testUnknownException(self):
         """Test raising an generic exception in a threaded handler."""
 
+        raised_errors = []
+
         def message(msg):
             raise ValueError("Did something wrong")
 
+        def catch_error(*args, **kwargs):
+            raised_errors.append(True)
+
+        sys.excepthook = catch_error
+
         self.stream_start()
         self.xmpp.add_event_handler('message', message)
 
@@ -90,7 +98,6 @@ class TestStreamExceptions(SleekTest):
           </message>
         """)
 
-        if sys.version_info < (3, 0):
         self.send("""
           <message type="error">
             <error type="cancel">
@@ -102,9 +109,9 @@ class TestStreamExceptions(SleekTest):
             </error>
           </message>
         """)
-        else:
-            # Unfortunately, tracebacks do not make for very portable tests.
-            pass
+
+        self.assertEqual(raised_errors, [True], "Exception was not raised: %s" % raised_errors)
+
 
 
 suite = unittest.TestLoader().loadTestsFromTestCase(TestStreamExceptions)