Tornado error when using matplotlib WabAgg backend

[Oswaldoj]

I installed matplotlib 1.3.1 under Windows 7, 32 bits, and Python 3.3. WebAgg seems to work fine, the graphics are beautifully displayed in my web browser (Chrome), but I am having some error messages from tornado that I do not understand. These errors happens as soon as I run the show() command on the Python console. Do you have any idea of what could be happening here?

Below is the error message content:

C:\Users\oswjimenez>py
Python 3.3.1 (v3.3.1:d9893d13c628, Apr  6 2013, 20:25:12) [MSC v.1600 32 bit (In
tel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from pylab import *
>>> x=linspace(1,10,100)
>>> y=sin(x)
>>> plot(x,y,'ro')
[<matplotlib.lines.Line2D object at 0x0310D3F0>]
>>> show()
Press Ctrl+C to stop server
ERROR:tornado.application:Uncaught exception GET /favicon.ico (127.0.0.1)
HTTPRequest(protocol='http', host='127.0.0.1:8988', method='GET', uri='/favicon.
ico', version='HTTP/1.1', remote_ip='127.0.0.1', headers={'Accept': '*/*', 'Acce
pt-Language': 'es-419,es;q=0.8,en;q=0.6', 'Connection': 'keep-alive', 'Accept-En
coding': 'gzip,deflate,sdch', 'Host': '127.0.0.1:8988', 'User-Agent': 'Mozilla/5
.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 S
afari/537.36'})
Traceback (most recent call last):
  File "C:\Python33\lib\site-packages\tornado-3.1.1-py3.3.egg\tornado\web.py", l
ine 1141, in _when_complete
    callback()
  File "C:\Python33\lib\site-packages\tornado-3.1.1-py3.3.egg\tornado\web.py", l
ine 1162, in _execute_method
    self._when_complete(method(*self.path_args, **self.path_kwargs),
  File "C:\Python33\lib\site-packages\matplotlib\backends\backend_webagg.py", li
ne 381, in get
    self.write(fd.read())
  File "C:\Python33\lib\encodings\cp1252.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x8f in position 120: char
acter maps to <undefined>
ERROR:tornado.access:500 GET /favicon.ico (127.0.0.1) 148.01ms

[tacaswell]

@mdboom Can you take a look at this?

[tacaswell]

I can not reproduce this on current master. @Oswaldoj If you still have this issue on current master please ping me to have this issue re-opened.