Saxon

The method GroundedValue.materialize(SequenceIterator) is documented to return the whole sequence backed by the sequence iterator, but some callers are assuming that it returns the residue, that is, the items that have not yet been read. For example, the new code for FocusTrackingIterator.getLength() is doing this. Generally, methods that pass around a SequenceIterator are interested only in the part of the sequence that has not yet been read.

This is causing a failure in position-0102 when I change 9.7 to use the same logic as 9.8 for computing last(). The test works in 9.8 because 9.8 is using a ListIterator rather than a ChainIterator.