Merge pull request #745 from minrk/history

Don't assume history requests succeed in qtconsole

closes gh-667

IPython/frontend/qt/console/console_widget.py

@@ -16,7 +16,7 b' from unicodedata import category'
 from IPython.external.qt import QtCore, QtGui
 
 # Local imports
-from IPython.config.configurable import Configurable
+from IPython.config.configurable import LoggingConfigurable
 from IPython.frontend.qt.rich_text import HtmlExporter
 from IPython.frontend.qt.util import MetaQObjectHasTraits, get_font
 from IPython.utils.text import columnize
@@ -39,7 +39,7 b' def is_letter_or_number(char):'
 # Classes
 #-----------------------------------------------------------------------------
 
-class ConsoleWidget(Configurable, QtGui.QWidget):
+class ConsoleWidget(LoggingConfigurable, QtGui.QWidget):
     """ An abstract base class for console-type widgets. This class has 
         functionality for:
 
@@ -170,7 +170,7 b' class ConsoleWidget(Configurable, QtGui.QWidget):'
             The parent for this widget.
         """
         QtGui.QWidget.__init__(self, parent)
-        Configurable.__init__(self, **kw)
+        LoggingConfigurable.__init__(self, **kw)
 
         # Create the layout and underlying text widget.
         layout = QtGui.QStackedLayout(self)

IPython/frontend/qt/console/ipython_widget.py

@@ -12,6 +12,7 b' import os.path'
 import re
 from subprocess import Popen
 import sys
+import time
 from textwrap import dedent
 
 # System library imports
@@ -104,6 +105,7 b' class IPythonWidget(FrontendWidget):'
     _payload_source_exit = zmq_shell_source + '.ask_exit'
     _payload_source_next_input = zmq_shell_source + '.set_next_input'
     _payload_source_page = 'IPython.zmq.page.page'
+    _retrying_history_request = False
 
     #---------------------------------------------------------------------------
     # 'object' interface
@@ -174,7 +176,25 b' class IPythonWidget(FrontendWidget):'
         """ Implemented to handle history tail replies, which are only supported
             by the IPython kernel.
         """
-        history_items = msg['content']['history']
+        content = msg['content']
+        if 'history' not in content:
+            self.log.error("History request failed: %r"%content)
+            if content.get('status', '') == 'aborted' and \
+                                            not self._retrying_history_request:
+                # a *different* action caused this request to be aborted, so
+                # we should try again.
+                self.log.error("Retrying aborted history request")
+                # prevent multiple retries of aborted requests:
+                self._retrying_history_request = True
+                # wait out the kernel's queue flush, which is currently timed at 0.1s
+                time.sleep(0.25)
+                self.kernel_manager.shell_channel.history(hist_access_type='tail',n=1000)
+            else:
+                self._retrying_history_request = False
+            return
+        # reset retry flag
+        self._retrying_history_request = False
+        history_items = content['history']
         items = [ line.rstrip() for _, _, line in history_items ]
         self._set_history(items)