urlencode images for rst files

closes  #5350

IPython/nbconvert/filters/markdown.py

@@ -103,7 +103,7 b" def markdown2html_marked(source, encoding='utf-8'):"
     return out.rstrip('\n')
 
 def markdown2rst(source):
-    """Convert a markdown string to LaTeX via pandoc.
+    """Convert a markdown string to ReST via pandoc.
 
     This function will raise an error if pandoc is not installed.
     Any error messages generated by pandoc are printed to stderr.

IPython/nbconvert/templates/rst.tpl

@@ -38,15 +38,15 b''
 {% endblock stream %}
 
 {% block data_svg %}
-.. image:: {{ output.svg_filename }}
+.. image:: {{ output.svg_filename|urlencode }}
 {% endblock data_svg %}
 
 {% block data_png %}
-.. image:: {{ output.png_filename }}
+.. image:: {{ output.png_filename|urlencode }}
 {% endblock data_png %}
 
 {% block data_jpg %}
-.. image:: {{ output.jpeg_filename }}
+.. image:: {{ output.jpeg_filename|urlencode }}
 {% endblock data_jpg %}
 
 {% block data_latex %}