Create DeepNestingParserTest.java (#577)

Author: pjfanning

src/test/java/com/fasterxml/jackson/dataformat/xml/stream/dos/DeepNestingParserTest.java

@@ -0,0 +1,54 @@
+package com.fasterxml.jackson.dataformat.xml.stream.dos;
+
+import com.ctc.wstx.stax.WstxInputFactory;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.dataformat.xml.XmlMapper;
+import com.fasterxml.jackson.dataformat.xml.XmlTestBase;
+
+public class DeepNestingParserTest extends XmlTestBase {
+
+    public void testDeepDoc() throws Exception
+    {
+        final XmlMapper xmlMapper = newMapper();
+        final String XML = createDeepNestedDoc(1050);
+        try (JsonParser p = xmlMapper.createParser(XML)) {
+            JsonToken jt;
+            while ((jt = p.nextToken()) != null) {
+
+            }
+            fail("expected JsonParseException");
+        } catch (JsonParseException e) {
+            assertTrue(e.getMessage().contains("Maximum Element Depth limit (1000) Exceeded"));
+        }
+    }
+
+    public void testDeepDocWithCustomDepthLimit() throws Exception
+    {
+        final WstxInputFactory wstxInputFactory = new WstxInputFactory();
+        wstxInputFactory.getConfig().setMaxElementDepth(2000);
+        final XmlMapper xmlMapper = new XmlMapper(wstxInputFactory);
+        final String XML = createDeepNestedDoc(1050);
+        try (JsonParser p = xmlMapper.createParser(XML)) {
+            JsonToken jt;
+            while ((jt = p.nextToken()) != null) {
+
+            }
+        }
+    }
+
+    private String createDeepNestedDoc(final int depth) {
+        StringBuilder sb = new StringBuilder();
+        sb.append("<root>");
+        for (int i = 0; i < depth; i++) {
+            sb.append("<leaf>");
+        }
+        sb.append("abc");
+        for (int i = 0; i < depth; i++) {
+            sb.append("</leaf>");
+        }
+        sb.append("</root>");
+        return sb.toString();
+    }
+}