Create reproducer test case for FasterXML#509

This adds two additional test cases. Those tests attempt to deserialize
the two classes Data and MetaData.

The MetaData class simply contains a list of Data objects. The Data
class contains a "key", which is derived from the attribute of the XML
node, and a "content" list, which is the arbitrary data stored inside
that node.

src/test/java/com/fasterxml/jackson/dataformat/xml/deser/UnexpectedNonWhitespaceText509Test.java

@@ -0,0 +1,110 @@
+package com.fasterxml.jackson.dataformat.xml.deser;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.JacksonException;
+import com.fasterxml.jackson.dataformat.xml.XmlMapper;
+
+import jakarta.xml.bind.annotation.XmlAccessType;
+import jakarta.xml.bind.annotation.XmlAccessorType;
+import jakarta.xml.bind.annotation.XmlAnyElement;
+import jakarta.xml.bind.annotation.XmlAttribute;
+import jakarta.xml.bind.annotation.XmlElement;
+import jakarta.xml.bind.annotation.XmlMixed;
+import jakarta.xml.bind.annotation.XmlRootElement;
+import jakarta.xml.bind.annotation.XmlType;
+
+public class UnexpectedNonWhitespaceText509Test {
+	@XmlRootElement(name = "data")
+	@XmlAccessorType(XmlAccessType.FIELD)
+	@XmlType(name = "Data", propOrder = { "key", "content" })
+	public static class Data {
+		@XmlMixed
+		@XmlAnyElement(lax = true)
+		protected List<Object> content;
+		@XmlAttribute(name = "key", required = true)
+		protected java.lang.String key;
+
+		public List<Object> getContent() {
+			if (content == null) {
+				content = new ArrayList<>();
+			}
+			return this.content;
+		}
+
+		public void setContent(List<Object> content) {
+			this.content = content;
+		}
+
+		public java.lang.String getKey() {
+			return key;
+		}
+
+		public void setKey(java.lang.String value) {
+			this.key = value;
+		}
+	}
+
+	@XmlRootElement(name = "metaData")
+	@XmlAccessorType(XmlAccessType.FIELD)
+	@XmlType(name = "MetaData", propOrder = { "data" })
+	public static class MetaData {
+		@XmlElement(required = true)
+		protected List<Data> data;
+
+		public List<Data> getData() {
+			if (data == null) {
+				data = new ArrayList<>();
+			}
+			return this.data;
+		}
+
+		public void setData(List<Data> data) {
+			this.data = data;
+		}
+
+		@Override
+		public String toString() {
+			return Objects.toString(data);
+		}
+	}
+
+	@Test
+	public void testDeSerData() {
+		Data value = deSer("<data key=\"MadeWith\">Text Editor</data>", Data.class);
+		assertEquals("\"key\" attribute not correctly deserialized", value.getKey(), "MadeWith");
+		assertEquals("\"content\" not correctly deserialized", value.getContent(), List.of("Text Editor"));
+	}
+
+	@Test
+	public void testDeSerMetaData() {
+		MetaData value = deSer("<metaData>\n" //
+				+ "    <data key=\"MadeWith\">Text Editor</data>\n" //
+				+ "    <data key=\"Version\">1.0.0</data>\n" //
+				+ "</metaData>", MetaData.class);
+		List<Data> entries = value.getData();
+		assertEquals("\"data\" not correctly deserialized", entries.size(), 2);
+		Data entry = entries.get(0);
+		assertEquals("\"key\" attribute not correctly deserialized", entry.getKey(), "MadeWith");
+		assertEquals("\"content\" not correctly deserialized", entry.getContent(), List.of("Text Editor"));
+		entry = entries.get(1);
+		assertEquals("\"key\" attribute not correctly deserialized", entry.getKey(), "Version");
+		assertEquals("\"content\" not correctly deserialized", entry.getContent(), List.of("1.0.0"));
+	}
+
+	private <T> T deSer(String xmlString, Class<T> clazz) {
+		try {
+			return new XmlMapper().readValue(xmlString, clazz);
+		} catch (JacksonException e) {
+			fail(e.getMessage());
+			return null;
+		}
+	}
+}