Bug summary

This code https://github.com/timhoffm/matplotlib/blob/7c378a8f3f30ce57c874a851f3af8af58f1ffdf6/lib/matplotlib/cbook/__init__.py#L403-L415 on the main branch (not released yet) falls into an infinite loop when there is only one double quotation because when s.find('"', quote_pos + 1) == -1 pos == 0

context:

• Support quoted strings in matplotlibrc #22589
• Escape # character in matplotlibrc #19288

Code for reproduction

from pathlib import Path

import matplotlib.pyplot as plt

Path("./test.mplstyle").write_text('grid.color: "aa')
plt.style.use("./test.mplstyle")

Actual outcome

The program doesn't exit.

Expected outcome

Show an error or set '"aa'.

Additional information

No response

Operating system

No response

Matplotlib Version

3.6.0.dev1816+gb9ae51ca8c.d20220311

Matplotlib Backend

No response

Python version

Python 3.10.0

Jupyter version

No response

Installation

No response