Fix an unlikely memory leak on conversion from string to float in the
function _Py_dg_strtod() used by float(str), complex(str),
pickle.load(), marshal.load(), etc.

Fix an unlikely memory leak in _Py_dg_strtod() on "undfl:" label:
rewrite memory management in this function to always release all
memory before exiting the function. Initialize variables to NULL, and
set them to NULL after calling Bfree() at the "cont:" label.

Note: Bfree(NULL) is well defined: it does nothing.

Sizeof new empty dict becomes 72 bytes from 240 bytes (amd64).
It is same size to empty dict created by dict.clear().

This is relevant for `debug doesnotexist()`, which would crash with a
NameError otherwise.

test_posix.PosixUidGidTests:

* Add tests for invalid uid/gid type (str)
* Add UID_OVERFLOW and GID_OVERFLOW constants to replace (1 << 32)

Initial patch written by David Malcolm.
Co-Authored-By: David Malcolm <dmalcolm@redhat.com>

Prevent conflicts with Linux dark themes
(and slightly darken calltip background).

* Refactor cookie path check as per RFC 6265

* Add tests for prefix match of path

* Add news entry

* Fix set_ok_path and refactor tests

* Use slice for last letter

Don't send cookies of domain A without Domain attribute to domain B when domain A is a suffix match of domain B while using a cookiejar with `http.cookiejar.DefaultCookiePolicy` policy.  Patch by Karthikeyan Singaravelan.

The overflow check was relying on undefined behaviour as it was using the result of the multiplication to do the check, and once the overflow has already happened, any operation on the result is undefined behaviour.

Some extra checks that exercise code paths related to this are also added.

d_initial, the first state of a particular DFA in the parser has always been initialized to 0 in the old pgen as well as the new pgen. As this value is not used and the first state of each DFA is assumed to be the first element in the array representing it, remove d_initial from the parser to reduce complexity.

The macros were working only because our usage happened to parse correctly.  Changing that usage (e.g. with pointers) would break the macros.  This fixes that.

This adds a `feature_version` flag to `ast.parse()` (documented) and `compile()` (hidden) that allow tweaking the parser to support older versions of the grammar. In particular if `feature_version` is 5 or 6, the hacks for the `async` and `await` keyword from PEP 492 are reinstated. (For 7 or higher, these are unconditionally treated as keywords, but they are still special tokens rather than `NAME` tokens that the parser driver recognizes.)



https://bugs.python.org/issue35975