plotting legends none

[segasai]

Hi,

It looks like in matplotlib-1.2.0 the behaviour of the legend has changed with regards to the labels which are "None".
In mpl 1.1.1 this code

import matplotlib.pyplot as plt

plt.plot([0,1],label=None)
plt.plot([0.1,1.2],label='dat2')

plt.legend()

plt.savefig('out.png')

was only creating the legend for the second line (that's what I would like to see),
but in 1.2.0 this code started to produce the legend for the first line with label='None'. See attached figures. To me this looks like a regression (which breaks a lot of my plots).

Thanks

Old behaviour:

New behaviour:

The suggested fix is here fe63689

[dmcdougall]

Fixed in #1611.