Rethrowing foreign exceptions

[purplesyringa]

The EH ABI seems to be internally inconsistent.

Section 1.2 reads:

The exception_cleanup routine is called whenever an exception object needs to be destroyed by a different runtime than the runtime which created the exception object, for instance if a Java exception is caught by a C++ catch handler. In such a case, a reason code (see above) indicates why the exception object needs to be deleted:

_URC_FOREIGN_EXCEPTION_CAUGHT = 1: This indicates that a different runtime caught this exception. Nested foreign exceptions, or rethrowing a foreign exception, result in undefined behaviour.

Section 1.6.4 reads:

Otherwise, a catch block catching a foreign exception is allowed:

• to resume normal execution, thereby stopping propagation of the foreign exception and deleting it, or

• to rethrow the foreign exception. In that case, the original exception object must be unaltered by the C++ runtime.

So is it allowed to rethrow a foreign exception or does that cause UB?