Provide a list of the command and argument to subprocess for PDF post-processor, which is a better way to avoid issues if there are spaces in the filename.

IPython/nbconvert/post_processors/pdf.py

@@ -1,53 +1,52 b''
 """
 Contains writer for writing nbconvert output to PDF.
 """
 #-----------------------------------------------------------------------------
 #Copyright (c) 2013, the IPython Development Team.
 #
 #Distributed under the terms of the Modified BSD License.
 #
 #The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import subprocess
 import os
-import shlex
 
-from IPython.utils.traitlets import Integer, Unicode, Bool
+from IPython.utils.traitlets import Integer, List, Bool
 
 from .base import PostProcessorBase
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class PDFPostProcessor(PostProcessorBase):
     """Writer designed to write to PDF files"""
 
     iteration_count = Integer(3, config=True, help="""
         How many times pdflatex will be called.
         """)
 
-    compiler = Unicode(u'pdflatex {0}', config=True, help="""
+    compiler = List(["pdflatex", "{filename}"], config=True, help="""
         Shell command used to compile PDF.""")
 
     verbose = Bool(False, config=True, help="""
         Whether or not to display the output of the compile call.
         """)
 
     def call(self, input):
             """
             Consume and write Jinja output a PDF.  
             See files.py for more...
             """        
-            command = self.compiler.format(shlex.quote(input))
-            self.log.info("Building PDF: `%s`", command)
+            command = [c.format(filename=input) for c in self.compiler]
+            self.log.info("Building PDF: `%s`", ' '.join(command))
             for index in range(self.iteration_count):
                 if self.verbose:
                     subprocess.Popen(command, shell=True)
                 else:
                     with open(os.devnull, 'wb') as null:
                         subprocess.Popen(command, shell=True, stdout=null)