There was a known issue for a long time that we occasionally encountered
strange "TypeError: an integer is required" and "RuntimeWarning: tp_compare
didn't return -1 or -2 for exception", as shown in the following unit test
log. The source of the former error was PyInt_AsLong(obj) being used by
IntegrationType_from_BPy_IntegrationType(obj), where "obj" was not properly
initialized in "__init__" before the converter was called. The TypeError
was left unattended for a while and showed up when a comparison occurred
and the TypeError was detected, which resulted in the latter warning.
> runTest (__main__.UnaryFunction1DDoubleInitTestCase) ...
> .\blender:211: RuntimeWarning: tp_compare didn't return -1 or -2 for exception
> ERROR
>
> ======================================================================
> ERROR: runTest (__main__.UnaryFunction1DDoubleInitTestCase)
> ----------------------------------------------------------------------
> Traceback (most recent call last):
> File "init_tests.py", line 211, in runTest
> TypeError: an integer is required
>
> ----------------------------------------------------------------------
* Also removed unnecessary error messages in "__init__" methods of
UnaryFunction1D types.
built-in types (the first was in revision 21877). When an exception
has raised within from the __init__ method of a user-defined class
derived from a built-in type (e.g., UnaryPredicate0D and
BinaryPredicate1D), some member variables of the base type are
left uninitialized, leading to a null pointer reference in the
"__dealloc__" function in the base type. To avoid this, pointer
checking was added in the deallocators of those built-in types that
can be used to define a subclass by a user.
callable(I, T) returns True when I is an object of a type T or
of a subtype of T. Also implemented a measure to avoid an
infinite loop when user-defined predicate and function classes
do not properly overload the __call__ method (including the
cases of directly instantiating the base classes such as
UnaryPredicate0D and BinaryPredicate1D).
