Bug report

It takes a long time when I plot long not-solid vline, set short ylim and save it.
The same bug happens at hline and xlim.

Code for reproduction

importmatplotlib.pyplotaspltimporttimeymax=1e7plt.figure()plt.ylim(0,ymax)plt.vlines(0,ymin=0,ymax=ymax,linestyles='dashed')t0=time.time()plt.savefig("test_0")# short timet1=time.time()print("{:.2f} [s]".format(t1-t0))plt.ylim(0,1)t2=time.time()plt.savefig("test_1")# long timet3=time.time()print("{:.2f} [s]".format(t3-t2))

Actual outcome

0.07 [s]93.95 [s]

Matplotlib version

• Operating system: Windows 10 Pro (64 bit)
• Matplotlib version: 3.0.3
• Matplotlib backend (print(matplotlib.get_backend())): module://ipykernel.pylab.backend_inline
• Python version: 3.6.8
• Jupyter version (if applicable): jupyter core: 4.5.0, jupyter-notebook: 6.0.0