Fix for starting the Qt console

IPython/core/inputsplitter.py

@@ -516,23 +516,31 b' class IPythonInputSplitter(InputSplitter):'
         self._buffer_raw = []
         self._validate = True
         
-        self.physical_line_transforms = physical_line_transforms or \
-                [leading_indent(),
-                 classic_prompt(),
-                 ipy_prompt(),
-                ]
+        if physical_line_transforms is not None:
+            self.physical_line_transforms = physical_line_transforms
+        else:
+            self.physical_line_transforms = [leading_indent(),
+                                             classic_prompt(),
+                                             ipy_prompt(),
+                                            ]
         
         self.assemble_logical_lines = assemble_logical_lines()
-        self.logical_line_transforms = logical_line_transforms or \
-                [cellmagic(),
-                 help_end(),
-                 escaped_commands(),
-                 assign_from_magic(),
-                 assign_from_system(),
-                ]
+        if logical_line_transforms is not None:
+            self.logical_line_transforms = logical_line_transforms
+        else:
+            self.logical_line_transforms = [cellmagic(),
+                                            help_end(),
+                                            escaped_commands(),
+                                            assign_from_magic(),
+                                            assign_from_system(),
+                                           ]
         
         self.assemble_python_lines = assemble_python_lines()
-        self.python_line_transforms = python_line_transforms or []
+        if python_line_transforms is not None:
+            self.python_line_transforms = python_line_transforms
+        else:
+            # We don't use any of these at present
+            self.python_line_transforms = []
     
     @property
     def transforms(self):

IPython/frontend/qt/console/frontend_widget.py

@@ -114,7 +114,10 b' class FrontendWidget(HistoryConsoleWidget, BaseFrontendMixin):'
     exit_requested = QtCore.Signal(object)
 
     # Protected class variables.
-    _prompt_transformer = IPythonInputSplitter(transforms=[classic_prompt()])
+    _prompt_transformer = IPythonInputSplitter(physical_line_transforms=[classic_prompt()],
+                                               logical_line_transforms=[],
+                                               python_line_transforms=[],
+                                              )
     _CallTipRequest = namedtuple('_CallTipRequest', ['id', 'pos'])
     _CompletionRequest = namedtuple('_CompletionRequest', ['id', 'pos'])
     _ExecutionRequest = namedtuple('_ExecutionRequest', ['id', 'kind'])

IPython/frontend/qt/console/ipython_widget.py

@@ -98,7 +98,10 b' class IPythonWidget(FrontendWidget):'
 
     # FrontendWidget protected class variables.
     _input_splitter_class = IPythonInputSplitter
-    _prompt_transformer = IPythonInputSplitter(transforms=[ipy_prompt()])
+    _prompt_transformer = IPythonInputSplitter(physical_line_transforms=[ipy_prompt()],
+                                               logical_line_transforms=[],
+                                               python_line_transforms=[],
+                                              )
 
     # IPythonWidget protected class variables.
     _PromptBlock = namedtuple('_PromptBlock', ['block', 'length', 'number'])