The `arraymodule`'s `b_getitem` function returns a `PyLong` converted
from `arrayobject`'s array, by dereferencing a pointer to `char`.
When the `char` type is `signed char`, the `if (x >= 128) x -= 256;` comparison/code is redundant because a `signed char` will have a value of `[-128, 127]` and so `x` will never be greater or equal than 128.
This check was indeed needed for situations where a given compiler would assume `char` being `unsigned char` which would make `x` in `[0, 256]` range.
However, the check can be removed if we cast the `ob_item` into a signed char pointer (`signed char*`) instead of `char*`.
This PR/commit introduces this change.
The final addition (cur += step) may overflow, so use size_t for "cur".
"cur" is always positive (even for negative steps), so it is safe to use
size_t here.
Co-Authored-By: Martin Panter <vadmium+py@gmail.com>
In _localemodule.c and selectmodule.c, remove dead code that would
cause double decrefs if run.
In addition, replace PyList_SetItem() with PyList_SET_ITEM() in cases
where a new list is populated and there is no possibility of an error.
In addition, check if the list changed size in the loop in array_array_fromlist().
Error messages when pass keyword arguments to some builtins that
don't support keyword arguments contained double parenthesis: "()()".
The regression was introduced by bpo-30534.
