XmlMapper regression in 3.2.0

[beikov]

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Describe the bug

XmlMapper wrongly interprets collection element null tag to mean the Collection to be null.

Version Information

3.2.0

Reproduction

xmlMapper.readValue("<Collection><e xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:nil=\"true\"/></Collection>", xmlMapper.constructType( new ParameterizedTypeImpl( CollectionWrapper.class, new Type[] {String.class}, null ));

with the model:

	@JsonRootName(value = "Collection")
	public static class CollectionWrapper<E> {
		@JacksonXmlElementWrapper(useWrapping = false)
		@JacksonXmlProperty(localName = "e")
		Collection<E> value;

		public CollectionWrapper() {
			this.value = new ArrayList<>();
		}

		public CollectionWrapper(Collection<E> value) {
			this.value = value;
		}
	}

Returns a CollectionWrapper with a null for value, whereas it should be a collection with a null element like in Jackson 3.1.4 and before.

Expected behavior

Return a CollectionWrapper with a collection containing a null value.

Additional context

No response

[beikov]

It seems like this regression is caused by #627
During debugging, I noticed that this is what makes the difference. If I call _xmlTokens.repeatStartElement() when it is now skipped with Jackson 3.2.0, the parsing succeeds again.