bug#30277: 26.0.91; Infinite recursion in python-nav-beginning-of-statement

[Eli Zaretskii]

> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Thu, 1 Feb 2018 15:28:36 +0300
> 
> On 1/29/18 1:42 AM, Ola Nilsson wrote:
> > The infinite recursion is triggered when the first line of a
> > python-mode buffer starts with space and ends with a backslash.
> > 
> > With emacs -Q
> > 
> > * create a new buffer
> > * M-x python-mode
> > * Insert SPACE \ ENTER
> > 
> > => Lisp nesting exceeds ‘max-lisp-eval-depth’
> > 
> > The infinite recursion is also triggered if the first line of a narrowed
> > region starts with space and ends on a backslash.
> 
> This seems to fix it for me. Please test thoroughly, I rarely ever use 
> python-mode myself.

Please push to the master branch, and thanks.