Fix None value in Pushforward

[campospinto]

there was a small bug in the Pushforward function, when no grid_local was passed for a mapping of Mapping type

I also added a unit test

[yguclu]

Good catch!

AFAIK the Pushforward class is only used by the PostProcessManager class (which always passes grid_local to it) and nowhere else in Psydac. So it is only tested indirectly in file test_postprocessing.py. So how did you find this bug?

[campospinto]

Good catch!

AFAIK the Pushforward class is only used by the PostProcessManager class (which always passes grid_local to it) and nowhere else in Psydac. So it is only tested indirectly in file test_postprocessing.py. So how did you find this bug?

It is used in the code for conga polar splines

[yguclu]

Good catch!
AFAIK the Pushforward class is only used by the PostProcessManager class (which always passes grid_local to it) and nowhere else in Psydac. So it is only tested indirectly in file test_postprocessing.py. So how did you find this bug?

It is used in the code for conga polar splines

I see... 😅... I must have decided to use it because it is quite a bit faster than the algorithms in pull_push.py.

The docstring of Pushforward says that the class constructor does not perform any checks on its arguments (probably because it was only used internally by the PostProcessManager class). Maybe we should add those checks now?

[yguclu]

@campospinto I have increased the tolerance in the failing unit test. Hopefully our workflows will pass now.