Philipp Stephani <p.stephani2@gmail.com> schrieb am Di., 28. Feb. 2017 um
22:32 Uhr:

> There appears to be an edge case caused by using `syntax-ppss' in a
> narrowed buffer during JIT lock inside of Python triple-quote strings.
> Unfortunately it is impossible to reproduce without manually
> destroying the syntactic information in the Python buffer, but it has
> been observed in practice.  In that case it can happen that the syntax
> caches get sufficiently out of whack so that there appear to be
> overlapping strings in the buffer.  As Python has no nested strings,
> this situation is impossible and leads to an infloop in
> `python-nav-end-of-statement'.  Protect against this by checking
> whether the search for the end of the current string makes progress.
>
> * python.el (python-nav-end-of-statement): Protect against infloop.
> * progmodes/python-tests.el
> (python-tests--python-nav-end-of-statement--infloop): Add unit test.
>

Pushed as 4fbd330fae.