Bug report

Bug summary

Contours created usingpyplot.contour are not correctly removed when labelling the contours usingplt.clabel invoked withinline=True and manual positions.

Code for reproduction

importnumpyasnpfrommatplotlibimportpyplotaspltx=np.linspace(-1,1)xx,yy=np.meshgrid(x,x)fig,axes=plt.subplots(1,2,True,True)manual=Noneforaxinaxes:cs=ax.contour(x,x,xx**2+yy**2)clabels=plt.clabel(cs,manual=manual)manual= [label.get_position()forlabelinclabels]

Expected outcome on the left, actual outcome on the right

Matplotlib version

• Operating system: Linux 273ceb986a84 4.9.49-mobyFix autofmt_xdate() when using in conjunction with twinx() #1 SMP Wed Sep 27 23:17:17 UTC 2017 x86_64 GNU/Linux
• Matplotlib version: 2.1.1
• Matplotlib backend (print(matplotlib.get_backend())): module://ipykernel.pylab.backend_inline
• Python version: 3.6.3
• Jupyter version (if applicable): 4.4.0
• Other libraries: numpy (1.13.3)

All libraries were installed using pip in a docker image derived frompython:3.