Open question, with respect to the original code:
76a160070b/include/pybind11/pybind11.h (L1510)
To me it looks like the exact situation marked as `std::shared_ptr<Good> gp1 = not_so_good.getptr();` here: https://en.cppreference.com/w/cpp/memory/enable_shared_from_this
The comment there is: `// undefined behavior (until C++17) and std::bad_weak_ptr thrown (since C++17)`
Does the existing code have UB pre C++17?
I'll leave handling of enable_shared_from_this for later, as the need arises.
* Demonstrate issue with weakref constructor overloads
* Fix weakref constructor to convert on being passed a non-weakref object
* Improve on nonlocal-scoped variable in test_weakref
* Keep backwards-compatibility by introducing PYBIND11_OBJECT_CVT_DEFAULT macro
* Simplify test_weakref
* Adding move_only_holder_caster `typename SFINAE = void` to enable external specializations.
* Adding SFINAE hook also to copyable_holder_caster, for uniformity, with comment to explain the purpose.
* When determining if a shared_ptr already exists, use a test on the weak_ptr instead of a try/catch block.
* When determining if a shared_ptr already exists, use a test on the weak_ptr instead of a try/catch block.
* weak_from_this is only available in C++17 and later
* Switch to use feature flag instead of C++ version flag.
* Add Microsoft-specific check.
* Avoid undefined preprocessor macro warning treated as error.
* Simplify shared_from_this in init_holder
* Include <version> in detail/common.h (~stolen~ borrowed from @bstaletic's #2816)
* Move class_::get_shared_from_this to detail::try_get_shared_from_this
* Simplify try_get_shared_from_this by using weak_ptr::lock()
Co-authored-by: Yannick Jadoul <yannick.jadoul@belgacom.net>
* Always call PyNumber_Index when casting from Python to a C++ integral type, also pre-3.8
* Fixed on PyPy
* Simplify use of PyNumber_Index, following @rwgk's idea, and ignore warnings in >=3.8
* Reproduce mismatch between pre-3.8 and post-3.8 behavior on __index__ throwing TypeError
* Fix tests on 3.6 <= Python < 3.8
* No, I don't have an uninitialized variable
* Fix use of __index__ on Python 2
* Make types in test_int_convert more ~boring~ descriptive
* Force the builtin module key to be the correct type.
Previously it was always going to be a std::string which converted into
unicode. Python 2 appears to want module keys to be normal str types, so
this was breaking code that expected plain string types in the
builtins.keys() data structure
* Add a simple unit test to ensure all built-in keys are str
* Update the unit test so it will also run on pypy
* Run pre-commit.
Co-authored-by: Jesse Clemens <jesse.clemens@sony.com>
