mode instead of the text mode (using the locale encoding) to avoid encoding
issues.

of the text mode (using the locale encoding) to avoid encoding issues.

This requires some trickery to properly save the exception state if the
generator creates its own exception state.

This prevents generator exception state from leaking into the caller.

Closes #12475.

qsize() raises NotImplementedError on OS X, don't use it.

Original patch by Nicolas Estibals.  My tweaks to the patch were mostly
style/cosmetic, and adding more tests.

freed by the garbage collector while the Heap lock is held.

freed by the garbage collector while the Heap lock is held.

the garbage collector while the Heap lock is held.