Bug: raise without an active exception re-raises the previous exception

[dmamelin]

Reproducer:

try:
    raise ValueError("Random error")
except ValueError as e:
    log.info(f"{type(e)}: {e}")

try:
    raise
except Exception as e:
    log.info(f"reraise {type(e)}: {e}")

Actual output:

<class 'ValueError'>: Random error
reraise <class 'ValueError'>: Random error

Expected output:

<class 'ValueError'>: Random error
reraise <class 'RuntimeError'>: No active exception to reraise