* Remove backtracking when parsing tarfile headers
* Rewrite PAX header parsing to be stricter
* Optimize parsing of GNU extended sparse headers v0.0
Co-authored-by: Kirill Podoprigora <kirill.bast9@mail.ru>
Co-authored-by: Gregory P. Smith <greg@krypto.org>
* urljoin() with relative reference "?" sets empty query and removes fragment.
* Preserve empty components (authority, params, query, fragment) in urljoin().
* Preserve empty components (authority, params, query) in urldefrag().
Also refactor the code and get rid of double _coerce_args() and
_coerce_result() calls in urljoin(), urldefrag(), urlparse() and
urlunparse().
When checking if the registering browser is the "OS preferred browser", do not use a substring search - that makes no sense: one can have a preferred browser that looks like a super-string of a known browser, e.g. "firefox-nightly" vs "firefox".
https://github.com/python/cpython/issues/108172 explains in more detail, and lays out a potential better future enhancement for this case of just using xdg-open. We'll go with this for now.
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Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
See https://github.com/python/cpython/issues/121313 for analysis, but this greatly reduces memory overallocation and overhead when multiprocessing is sending non-small data over its pipes between processes.
This checks are redundant in normal circumstances and can only work if
the extension registry was intentionally broken.
* The Python implementation now raises exception for the extension code
with false boolean value.
* Simplify the C code. RuntimeError is now raised in explicit checks.
* Add many tests.
* Replace PyLong_AS_LONG() with PyLong_AsLong().
* Call PyLong_AsLong() only once per the replacement code.
* Use PyMapping_GetOptionalItem() instead of PyObject_GetItem().
The `zip_next` function uses a common optimization technique for methods
that generate tuples. The iterator maintains an internal reference to
the returned tuple. When the method is called again, it checks if the
internal tuple's reference count is 1. If so, the tuple can be reused.
However, this approach is not safe under the free-threading build:
after checking the reference count, another thread may perform the same
check and also reuse the tuple. This can result in a double decref on
the items of the replaced tuple and a double incref (memory leak) on
the items of the tuple being set.
This adds a function, `_PyObject_IsUniquelyReferenced` that
encapsulates the stricter logic necessary for the free-threaded build:
the internal tuple must be owned by the current thread, have a local
refcount of one, and a shared refcount of zero.
* Make `weakref.WeakSet` safe against concurrent mutations while it is being iterated.
`_IterationGuard` is no longer used for `WeakSet`, it now relies on copying the underlying set which is an atomic operation while iterating so that it can be modified by other threads.