Bug report

Bug summary

Python crashes on plotting contour of array with two dimensions of size 1.

Code for reproduction

import numpy as np
import matplotlib.pyplot as plt

im = np.array([[0]])
plt.contour(im)

Actual outcome

Python interpreter craches, with this message:
Floating point exception (core dumped) 

Expected outcome
This is the output I get on Python 2.6.6:
ValueError: zero-size array to reduction operation minimum which has no identity

Matplotlib version
Fedora 23, with Matplotlib 2.0.0 and numpy 1.12.0 installed using pip.