Setup

matplotlib.__version__ = 1.5.1
matplotlib.__version__numpy__ = 1.6
Python 3.5.1, IPython 4.1.2 running under anaconda
OS: Red Hat 6.5

Matplotlib installed with conda install matplotlib.

Issue

Supplying None (the object, not the string) linestyle parameter to plot (and possible others) raises an error instead of going through the default cycler for that property. I would expect the following to work, but it does not:

>>> import matplotlib.pyplot as plt
>>> plt.plot(range(5), range(5), linestyle=None)
...
TypeError: object of type 'NoneType' has no len()

The expected behavior would be that all lines are drawn 'solid'.

If this is something that is worth fixing, I can take a look in a couple of days and maybe add code similar to what is done for the color argument. The docs would need to be updated too.