Fix Windows-specific bug in path handling for Qt console.

IPython/frontend/qt/console/frontend_widget.py

@@ -435,7 +435,7 b' class FrontendWidget(HistoryConsoleWidget, BaseFrontendMixin):'
         """ Attempts to execute file with 'path'. If 'hidden', no output is
             shown.
         """
-        self.execute('execfile("%s")' % path, hidden=hidden)
+        self.execute('execfile(%r)' % path, hidden=hidden)
 
     def interrupt_kernel(self):
         """ Attempts to interrupt the running kernel.

IPython/frontend/qt/console/ipython_widget.py

@@ -8,8 +8,10 b''
 
 # Standard library imports
 from collections import namedtuple
+import os.path
 import re
 from subprocess import Popen
+import sys
 from textwrap import dedent
 
 # System library imports
@@ -233,6 +235,10 b' class IPythonWidget(FrontendWidget):'
     def execute_file(self, path, hidden=False):
         """ Reimplemented to use the 'run' magic.
         """
+        # Use forward slashes on Windows to avoid escaping each separator.
+        if sys.platform == 'win32':
+            path = os.path.normpath(path).replace('\\', '/')
+
         self.execute('%%run %s' % path, hidden=hidden)
 
     #---------------------------------------------------------------------------