cpdef methods that return C types like Stream.get_file_position must have an except clause or the exception won't propagate

[Keithcat1]

https://cython.readthedocs.io/en/latest/src/userguide/language_basics.html#error-return-values[](https://cython.readthedocs.io/en/latest/src/userguide/language_basics.html#error-return-values)

[Timtam]

thank you. I would have noticed as soon as a test tries to handle exactly such a situation. I'll leave it open as a reminder until i can be sure to have fixed the corresponding methods.