Check cwrap types when calling via pybind

[eivindjahren]

Adds TypeError for calls to methods that would lead to undefined behavior.

In order for this to not be a breaking change, we have to be sure that the previous behavior was not defined, at least not in documentation.

The simplest case is that whenever from_cwrap<T>(self) is called, somehow inserting anything other than the instance as self (is that even possible?) would not be supported.

Here are some of the less simple cases:

In the call to _rd_sum._fread_alloc, data_files is a local variable, so this is unproblematic. Similarly, the following have also always been unproblematic:

• _rd_sum._init_pandas_frame, keywords
• _rd_sum._init_pandas_frame_interp, keywords
• _rd_sum._init_pandas_frame_interp, time_points
• _rd_sum._dump_csv_line, key_words
• _rd_sum._export_csv, var_list
• _grid._fprintf_grdecl2, output_unit
• _grid._fprintf_GRID2, output_unit
• _grid._fprintf_EGRID2, output_unit
• _grid._compressed_kw_copy, kw_copy
• _grid._global_kw_copy, kw_copy
• _kw._fprintf_grdecl, file
• _grid._fwrite_grdecl, file
• _grid._fprintf_grdecl2, file
• _rd_sum._dump_csv_line, file
• _grid._equal, other

For the following function, parameter combinations the following holds: In the call to the function, giving None or an invalid BaseCClass would result in UB. After this change all UB cases are TypeError.

• _rd_sum._resample, time_points
• _grid._grdecl_create, zcorn
• _grid._grdecl_create, coord
• _grid._fwrite_grdecl, kw
• _grid._load_column, kw
• _grid._load_column, column
• _grid._fprintf_grdecl2, kw
• _kw._load_grdecl, cfile
• _kw._load_grdecl, kw

The following would give a different exception if given None, but potentially a UB if a different BaseCClass. We have now introduced a TypeError instead.

• _grid._compressed_kw_copy, kw
• _grid._global_kw_copy, kw
• _grid._export_data_as_int, kw
• _grid._export_data_as_double, kw

For _grid._grdecl_create, actnumand_grid._grdecl_create, mapaxes, the only difference is that these could always be None. However, we have now introduced a TypeError if not the correct BaseCClass.

[Copilot]

Pull request overview

This PR centralizes the pybind “cwrap handle → native pointer” conversion logic and adds runtime type-checking to prevent undefined behavior when Python callers pass incorrect object types into pybind/C++ entrypoints.

Changes:

• Introduces a shared from_cwrap<T>(handle) implementation that validates Python object types before extracting _BaseCClass__c_pointer.
• Updates _grid, _kw, _rd_sum, and _fortio pybind modules to use the shared helper and adds an optional-kw variant for nullable keyword parameters.
• Adds/updates Python tests to assert TypeError is raised for wrong-type inputs instead of risking UB.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
tests/rd_tests/test_rd_sum.py	Adds tests ensuring wrong-type keywords / time_points raise TypeError.
tests/rd_tests/test_rd_grid_misc.py	Switches to public Grid.load_column and adds wrong-type argument TypeError tests.
tests/rd_tests/test_grid.py	Adds Grid.create wrong-type argument TypeError tests and verifies None is accepted where intended.
lib/resdata/rd_sum_pybind.cpp	Replaces local cwrap casting helper with shared implementation.
lib/resdata/rd_kw_pybind.cpp	Replaces local cwrap casting helper with shared implementation.
lib/resdata/rd_grid_pybind.cpp	Replaces local cwrap casting helper with shared implementation and uses nullable kw conversion for actnum/mapaxes.
lib/resdata/fortio_pybind.cpp	Replaces local cwrap casting helper with shared implementation.
lib/resdata/cwrap_pybind.cpp	New shared implementation providing typed from_cwrap<T> specializations.
lib/private-include/detail/resdata/cwrap_pybind.hpp	New header exposing from_cwrap<T> and optional-kw helper to pybind modules.
lib/CMakeLists.txt	Adds cwrap_pybind.cpp to all relevant pybind extension modules and updates include paths.

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[ajaust]

Nice changes! I only have a single point that might need validation (about changing some target_include_directories).