Update release notes wrt #3419

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -1432,3 +1432,8 @@ Matthieu Finiasz (finiasz@github)
 ZeyuCai@github:
   * Contributed #3314: Four Flaky Tests Detected in 2.14
   (2.14.0)
+
+Gary Morgan (morganga@github)
+  * Contributed #3419: Improve performance of `UnresolvedForwardReference` for
+    forward reference resolution
+  (2.14.0)

release-notes/VERSION-2.x

@@ -9,6 +9,9 @@ Project: jackson-databind
 #3373: Change `TypeSerializerBase` to skip `generator.writeTypePrefix()`
   for `null` typeId
 #3405: Create DataTypeFeature abstraction (for JSTEP-7) with placeholder features
+#3419: Improve performance of `UnresolvedForwardReference` for forward reference
+ resolution
+(contributed by Gary M)
 #3421: Implement `JsonNodeFeature.READ_NULL_PROPERTIES` to allow skipping of
   JSON `null` values on reading
 

src/main/java/com/fasterxml/jackson/databind/deser/DefaultDeserializationContext.java

@@ -168,7 +168,8 @@ public void checkUnresolvedObjectId() throws UnresolvedForwardReference
                 continue;
             }
             if (exception == null) {
-                exception = new UnresolvedForwardReference(getParser(), "Unresolved forward references for: ")._fillInStackTrace();
+                exception = new UnresolvedForwardReference(getParser(), "Unresolved forward references for: ")
+                        .withStackTrace();
             }
             Object key = roid.getKey().key;
             for (Iterator<Referring> iterator = roid.referringProperties(); iterator.hasNext(); ) {

src/main/java/com/fasterxml/jackson/databind/deser/UnresolvedForwardReference.java

@@ -37,24 +37,6 @@ public UnresolvedForwardReference(JsonParser p, String msg) {
         _unresolvedIds = new ArrayList<UnresolvedId>();
     }
 
-    /**
-     * @deprecated Since 2.7
-     */
-    @Deprecated // since 2.7
-    public UnresolvedForwardReference(String msg, JsonLocation loc, ReadableObjectId roid) {
-        super(msg, loc);
-        _roid = roid;
-    }
-
-    /**
-     * @deprecated Since 2.7
-     */
-    @Deprecated // since 2.7
-    public UnresolvedForwardReference(String msg) {
-        super(msg);
-        _unresolvedIds = new ArrayList<UnresolvedId>();
-    }
-
     /*
     /**********************************************************
     /* Accessor methods
@@ -98,12 +80,27 @@ public String getMessage()
         return sb.toString();
     }
 
+    /**
+     * This method is overridden to prevent filling of the stack trace when
+     * constructors are called (unfortunately alternative constructors can
+     * not be used due to historical reasons).
+     * To explicitly fill in stack traces method {@link #withStackTrace()}
+     * needs to be called after construction.
+     *
+     * @since 2.14
+     */
     @Override
     public synchronized UnresolvedForwardReference fillInStackTrace() {
         return this;
     }
 
-    public synchronized UnresolvedForwardReference _fillInStackTrace() {
+    /**
+     * "Mutant" factory method for filling in stack trace; needed since the default
+     * constructors will not fill in stack trace.
+     *
+     * @since 2.14
+     */
+    public UnresolvedForwardReference withStackTrace() {
         super.fillInStackTrace();
         return this;
     }

src/test/java/com/fasterxml/jackson/databind/exc/UnresolvedForwardReferenceTest.java

@@ -0,0 +1,26 @@
+package com.fasterxml.jackson.databind.exc;
+
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.BaseMapTest;
+import com.fasterxml.jackson.databind.deser.UnresolvedForwardReference;
+
+public class UnresolvedForwardReferenceTest extends BaseMapTest
+{
+    private final JsonFactory JSON_F = sharedMapper().getFactory();
+
+    public void testWithAndWithoutStackTraces() throws Exception
+    {
+        try (JsonParser p = JSON_F.createParser("{}")) {
+            UnresolvedForwardReference e = new UnresolvedForwardReference(p, "test");
+            StackTraceElement[] stack = e.getStackTrace();
+            assertEquals(0, stack.length);
+
+            e = e.withStackTrace();
+            stack = e.getStackTrace();
+            if (stack.length < 1) {
+                fail("Should have filled in stack traces, only got: "+stack.length);
+            }
+        }
+    }
+}