Add a (failing) test for #3582

src/test/java/com/fasterxml/jackson/databind/deser/dos/DeepArrayWrappingForDeser3582Test.java

@@ -0,0 +1,41 @@
+package com.fasterxml.jackson.databind.deser.dos;
+
+import com.fasterxml.jackson.databind.*;
+
+public class DeepArrayWrappingForDeser3582Test extends BaseMapTest
+{
+    // 23-Aug-2022, tatu: Before fix, fails with 5000
+    //    (but passes with 2000)
+//    private final static int TOO_DEEP_NESTING = 4999;
+    private final static int TOO_DEEP_NESTING = 1999;
+
+    private final ObjectMapper MAPPER = jsonMapperBuilder()
+            .enable(DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS)
+            .build();
+
+    public void testArrayWrapping() throws Exception
+    {
+        final String doc = _nestedDoc(TOO_DEEP_NESTING, "[ ", "] ", "{}");
+        Point p = MAPPER.readValue(doc, Point.class);
+        assertNotNull(p);
+    }
+
+    private String _nestedDoc(int nesting, String open, String close, String content) {
+        StringBuilder sb = new StringBuilder(nesting * (open.length() + close.length()));
+        for (int i = 0; i < nesting; ++i) {
+            sb.append(open);
+            if ((i & 31) == 0) {
+                sb.append("\n");
+            }
+        }
+        sb.append("\n").append(content).append("\n");
+        for (int i = 0; i < nesting; ++i) {
+            sb.append(close);
+            if ((i & 31) == 0) {
+                sb.append("\n");
+            }
+        }
+        return sb.toString();
+    }
+
+}