AbstractStaxWriterTest.marshalWithBothRepairingModes calls marshall, which purports to create a StaxWriter with repairing mode set to the value of a parameter. Unfortunately, when it actually creates the StaxWriter, it does so with a form of the constructor that does not specify the repairing mode, and that constructor simply calls another form of the constructor with repairing mode set to true.
The attached patch fixes this problem by calling the appropriate constructor. You can see that it causes the existing tests to fail, at least with the Woodstox implementation, which is the only one I tried it with. I also added another test for an issue I've noticed where two elements with the same prefix in a row doesn't work the second time in non-repairing mode.